Merge branch 'master' of https://git.z.xinu.tv/wathiede/raytracers

rtiow/renderer/Cargo.toml

@@ -0,0 +1,30 @@
+[package]
+name = "renderer"
+version = "0.1.0"
+authors = ["Bill Thiede <git@xinu.tv>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+[[bench]]
+harness = false
+name = "spheres"
+
+[dependencies]
+chrono = "*"
+core_affinity = "0.5"
+cpuprofiler = { version = "0.0.3", optional = true }
+image = "0.19.0"
+lazy_static = "1.1.0"
+log = "0.4.5"
+num_cpus = "1.8.0"
+rand = "0.5.5"
+serde = "1.0.79"
+serde_derive = "1.0.79"
+serde_json = "1.0.41"
+structopt = "0.2.10"
+
+[dev-dependencies]
+criterion = "0.2"
+
+[features]
+profile = ["cpuprofiler"]

rtiow/renderer/benches/spheres.rs

@@ -0,0 +1,37 @@
+#[macro_use]
+extern crate criterion;
+
+use criterion::Criterion;
+use criterion::ParameterizedBenchmark;
+
+use rtiow::hitable::Hit;
+use rtiow::material::Lambertian;
+use rtiow::ray::Ray;
+use rtiow::sphere::Sphere;
+use rtiow::texture::ConstantTexture;
+use rtiow::vec3::Vec3;
+
+fn criterion_benchmark(c: &mut Criterion) {
+    let sphere = Sphere::new(
+        Vec3::new(0., 0., 0.),
+        1.,
+        Lambertian::new(ConstantTexture::new([1., 0., 0.])),
+    );
+    let rays = vec![
+        // Hit
+        Ray::new([0., 0., -2.], [0., 0., 1.], 0.),
+        // Miss
+        Ray::new([0., 0., -2.], [0., 0., -1.], 0.),
+    ];
+    c.bench(
+        "sphere",
+        ParameterizedBenchmark::new(
+            "Sphere",
+            move |b, r| b.iter(|| sphere.hit(*r, 0., 1.)),
+            rays,
+        ),
+    );
+}
+
+criterion_group!(benches, criterion_benchmark);
+criterion_main!(benches);

rtiow/renderer/src/aabb.rs

@@ -0,0 +1,172 @@
+use std::fmt;
+
+use crate::ray::Ray;
+use crate::vec3::Vec3;
+
+#[derive(Debug, Clone, PartialEq)]
+pub struct AABB {
+    bounds: [Vec3; 2],
+}
+
+impl fmt::Display for AABB {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "({})-({})", self.bounds[0], self.bounds[1])
+    }
+}
+
+fn min(x: f32, y: f32) -> f32 {
+    if x < y {
+        x
+    } else {
+        y
+    }
+}
+
+fn max(x: f32, y: f32) -> f32 {
+    if x > y {
+        x
+    } else {
+        y
+    }
+}
+
+impl AABB {
+    pub fn new(min: Vec3, max: Vec3) -> AABB {
+        AABB { bounds: [min, max] }
+    }
+
+    pub fn volume(&self) -> f32 {
+        (self.min().x - self.max().x).abs()
+            * (self.min().y - self.max().y).abs()
+            * (self.min().z - self.max().z).abs()
+    }
+
+    pub fn longest_axis(&self) -> usize {
+        let xd = (self.min().x - self.max().x).abs();
+        let yd = (self.min().y - self.max().y).abs();
+        let zd = (self.min().z - self.max().z).abs();
+
+        if xd >= yd && xd >= zd {
+            return 0;
+        }
+        if yd >= xd && yd >= zd {
+            return 1;
+        }
+        2
+    }
+
+    pub fn mid_point(&self) -> Vec3 {
+        self.bounds[0] + (self.bounds[1] - self.bounds[0]) / 2.
+    }
+
+    pub fn min(&self) -> Vec3 {
+        self.bounds[0]
+    }
+    pub fn max(&self) -> Vec3 {
+        self.bounds[1]
+    }
+
+    pub fn hit2(&self, r: Ray, t_min: f32, t_max: f32) -> bool {
+        let mut t_min = t_min;
+        let mut t_max = t_max;
+        for axis in 0..3 {
+            let d_inv = 1.0 / r.direction[axis];
+            let t0 = min(
+                (self.min()[axis] - r.origin[axis]) * d_inv,
+                (self.max()[axis] - r.origin[axis]) * d_inv,
+            );
+            let t1 = max(
+                (self.min()[axis] - r.origin[axis]) * d_inv,
+                (self.max()[axis] - r.origin[axis]) * d_inv,
+            );
+            t_min = max(t0, t_min);
+            t_max = min(t1, t_max);
+            if t_max <= t_min {
+                return false;
+            }
+        }
+        true
+    }
+
+    pub fn hit_precompute(&self, r: Ray, t0: f32, t1: f32) -> bool {
+        // TODO(wathiede): this has bugs.
+        let mut t_min = (self.bounds[r.sign[0]].x - r.origin.x) * r.inv_direction.x;
+        let mut t_max = (self.bounds[1 - r.sign[0]].x - r.origin.x) * r.inv_direction.x;
+        let t_y_min = (self.bounds[r.sign[0]].y - r.origin.y) * r.inv_direction.y;
+        let t_y_max = (self.bounds[1 - r.sign[0]].y - r.origin.y) * r.inv_direction.y;
+
+        if t_min > t_y_max || t_y_min > t_max {
+            return false;
+        }
+
+        if t_y_min > t_min {
+            t_min = t_y_min;
+        }
+        if t_y_max < t_max {
+            t_max = t_y_max;
+        }
+
+        let t_z_min = (self.bounds[r.sign[2]].z - r.origin.z) * r.inv_direction.z;
+        let t_z_max = (self.bounds[1 - r.sign[2]].z - r.origin.z) * r.inv_direction.z;
+        if t_min > t_z_max || t_z_min > t_max {
+            return false;
+        }
+        if t_z_min > t_min {
+            t_min = t_z_min;
+        }
+        if t_z_max < t_max {
+            t_max = t_z_max;
+        }
+        t_min < t1 && t_max > t0
+    }
+
+    pub fn hit(&self, r: Ray, t_min: f32, t_max: f32) -> bool {
+        let mut t_min = t_min;
+        let mut t_max = t_max;
+        for axis in 0..3 {
+            let t0 = ((self.min()[axis] - r.origin[axis]) * r.inv_direction[axis])
+                .min((self.max()[axis] - r.origin[axis]) * r.inv_direction[axis]);
+            let t1 = ((self.min()[axis] - r.origin[axis]) * r.inv_direction[axis])
+                .max((self.max()[axis] - r.origin[axis]) * r.inv_direction[axis]);
+            t_min = t0.max(t_min);
+            t_max = t1.min(t_max);
+            if t_max <= t_min {
+                return false;
+            }
+        }
+        true
+    }
+
+    pub fn hit_fast(&self, r: Ray, _t_min: f32, _t_max: f32) -> bool {
+        let b = self;
+        let mut t1 = (b.min()[0] - r.origin[0]) * 1. / r.direction[0];
+        let mut t2 = (b.max()[0] - r.origin[0]) * 1. / r.direction[0];
+
+        let mut tmin = t1.min(t2);
+        let mut tmax = t1.max(t2);
+
+        for i in 1..3 {
+            t1 = (b.min()[i] - r.origin[i]) * 1. / r.direction[i];
+            t2 = (b.max()[i] - r.origin[i]) * 1. / r.direction[i];
+
+            tmin = tmin.max(t1.min(t2));
+            tmax = tmax.min(t1.max(t2));
+        }
+
+        tmax > tmin.max(0.0)
+    }
+}
+
+pub fn surrounding_box(box0: &AABB, box1: &AABB) -> AABB {
+    let min = Vec3::new(
+        box0.min().x.min(box1.min().x),
+        box0.min().y.min(box1.min().y),
+        box0.min().z.min(box1.min().z),
+    );
+    let max = Vec3::new(
+        box0.max().x.max(box1.max().x),
+        box0.max().y.max(box1.max().y),
+        box0.max().z.max(box1.max().z),
+    );
+    AABB::new(min, max)
+}

rtiow/renderer/src/build.rs

@@ -0,0 +1,5 @@
+extern crate askama;
+
+fn main() {
+    askama::rerun_if_templates_changed();
+}

rtiow/renderer/src/bvh.rs

@@ -0,0 +1,300 @@
+use std;
+use std::fmt;
+use std::time::Instant;
+
+use log::info;
+use rand;
+use rand::Rng;
+
+use crate::aabb::surrounding_box;
+use crate::aabb::AABB;
+use crate::hitable::Hit;
+use crate::hitable::HitRecord;
+use crate::ray::Ray;
+
+enum BVHNode {
+    Leaf(Box<dyn Hit>),
+    Branch {
+        left: Box<BVHNode>,
+        right: Box<BVHNode>,
+        bbox: Option<AABB>,
+    },
+}
+
+impl fmt::Display for BVHNode {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            BVHNode::Leaf(ref hit) => write!(
+                f,
+                "Leaf: {}",
+                hit.bounding_box(0., 0.)
+                    .map_or("NO BBOX".to_owned(), |bb| bb.to_string())
+            ),
+            BVHNode::Branch { bbox, .. } => write!(
+                f,
+                "Branch: {}",
+                // TODO(wathiede): removing this .clone() results in a complaint about moving out
+                // of a borrow.
+                bbox.clone()
+                    .map_or("NO BBOX".to_owned(), |bb| bb.to_string())
+            ),
+        }
+    }
+}
+
+// Lint is wrong when dealing with Box<Trait>
+#[allow(clippy::borrowed_box)]
+fn box_x_compare(ah: &Box<dyn Hit>, bh: &Box<dyn Hit>) -> std::cmp::Ordering {
+    match (ah.bounding_box(0., 0.), bh.bounding_box(0., 0.)) {
+        (Some(box_left), Some(box_right)) => {
+            box_left.min().x.partial_cmp(&box_right.min().x).unwrap()
+        }
+        _ => panic!("hit missing bounding box"),
+    }
+}
+
+#[allow(clippy::borrowed_box)]
+fn box_y_compare(ah: &Box<dyn Hit>, bh: &Box<dyn Hit>) -> std::cmp::Ordering {
+    match (ah.bounding_box(0., 0.), bh.bounding_box(0., 0.)) {
+        (Some(box_left), Some(box_right)) => {
+            box_left.min().y.partial_cmp(&box_right.min().y).unwrap()
+        }
+        _ => panic!("hit missing bounding box"),
+    }
+}
+
+#[allow(clippy::borrowed_box)]
+fn box_z_compare(ah: &Box<dyn Hit>, bh: &Box<dyn Hit>) -> std::cmp::Ordering {
+    match (ah.bounding_box(0., 0.), bh.bounding_box(0., 0.)) {
+        (Some(box_left), Some(box_right)) => {
+            box_left.min().z.partial_cmp(&box_right.min().z).unwrap()
+        }
+        _ => panic!("hit missing bounding box"),
+    }
+}
+
+// Return the first element from the vector, which should be the only element.
+// TODO(wathiede): we really want a .first_into() (.first() doesn't work because it
+// returns a reference.)
+fn vec_first_into<T>(v: Vec<T>) -> T {
+    if v.len() != 1 {
+        panic!(format!(
+            "vec_first_into called for vector length != 1, length {}",
+            v.len()
+        ));
+    }
+    v.into_iter().next().unwrap()
+}
+
+fn vec_split_into<T>(v: Vec<T>, offset: usize) -> (Vec<T>, Vec<T>) {
+    let mut left_half = Vec::new();
+    let mut right_half = Vec::new();
+    v.into_iter().enumerate().for_each(|(i, h)| {
+        if i < offset {
+            left_half.push(h);
+        } else {
+            right_half.push(h);
+        }
+    });
+    (left_half, right_half)
+}
+
+impl BVHNode {
+    fn new(l: Vec<Box<dyn Hit>>, t_min: f32, t_max: f32) -> BVHNode {
+        if l.len() == 1 {
+            BVHNode::Leaf(vec_first_into(l))
+        } else {
+            let mut l: Vec<Box<dyn Hit>> = l.into_iter().collect();
+            let mut rng = rand::thread_rng();
+            match rng.gen_range(0, 3) {
+                0 => l.sort_by(box_x_compare),
+                1 => l.sort_by(box_y_compare),
+                2 => l.sort_by(box_z_compare),
+                val => panic!("unknown axis {}", val),
+            }
+
+            let half = l.len() / 2;
+            let (left_half, right_half) = vec_split_into(l, half);
+            let left = Box::new(BVHNode::new(left_half, t_min, t_max));
+            let right = Box::new(BVHNode::new(right_half, t_min, t_max));
+            let bbox = BVHNode::surrounding_box(left.as_ref(), right.as_ref(), t_min, t_max);
+            BVHNode::Branch { left, right, bbox }
+        }
+    }
+
+    fn surrounding_box(left: &dyn Hit, right: &dyn Hit, t_min: f32, t_max: f32) -> Option<AABB> {
+        match (
+            left.bounding_box(t_min, t_max),
+            right.bounding_box(t_min, t_max),
+        ) {
+            (Some(left_bbox), Some(right_bbox)) => Some(surrounding_box(&left_bbox, &right_bbox)),
+            (None, Some(right_bbox)) => Some(right_bbox),
+            (Some(left_bbox), None) => Some(left_bbox),
+            (None, None) => None,
+        }
+    }
+
+    fn volume(&self) -> f32 {
+        let bbox = self.bounding_box(0., 0.).unwrap();
+        (bbox.min().x - bbox.max().x).abs()
+            * (bbox.min().y - bbox.max().y).abs()
+            * (bbox.min().z - bbox.max().z).abs()
+    }
+}
+
+impl Hit for BVHNode {
+    fn hit(&self, r: Ray, t_min: f32, t_max: f32) -> Option<HitRecord> {
+        match self {
+            BVHNode::Leaf(ref hit) => hit.hit(r, t_min, t_max),
+            BVHNode::Branch {
+                ref left,
+                ref right,
+                ref bbox,
+            } => match bbox {
+                Some(ref bbox) => {
+                    if bbox.hit(r, t_min, t_max) {
+                        match (left.hit(r, t_min, t_max), right.hit(r, t_min, t_max)) {
+                            (Some(hit_left), Some(hit_right)) => {
+                                if hit_left.t < hit_right.t {
+                                    Some(hit_left)
+                                } else {
+                                    Some(hit_right)
+                                }
+                            }
+                            (Some(hit_left), None) => Some(hit_left),
+                            (None, Some(hit_right)) => Some(hit_right),
+                            (None, None) => None,
+                        };
+                    }
+                    None
+                }
+                None => None,
+            },
+        }
+    }
+
+    fn bounding_box(&self, t_min: f32, t_max: f32) -> Option<AABB> {
+        match self {
+            BVHNode::Leaf(ref hit) => hit.bounding_box(t_min, t_max),
+            BVHNode::Branch { ref bbox, .. } => bbox.clone(),
+        }
+    }
+}
+
+pub struct BVH {
+    root: BVHNode,
+}
+
+impl BVH {
+    pub fn new(l: Vec<Box<dyn Hit>>, t_min: f32, t_max: f32) -> BVH {
+        let count = l.len();
+        let start = Instant::now();
+        let bvh = BVH {
+            root: BVHNode::new(l, t_min, t_max),
+        };
+        let runtime = start.elapsed();
+        info!(
+            "BVH build time {}.{} seconds for {} hitables",
+            runtime.as_secs(),
+            runtime.subsec_millis(),
+            count
+        );
+        bvh
+    }
+}
+
+fn print_tree(f: &mut fmt::Formatter, depth: usize, bvhn: &BVHNode) -> fmt::Result {
+    let vol = bvhn.volume();
+    writeln!(f, "{:.*}{}{}", 2, vol, " ".repeat(depth * 2), bvhn)?;
+    if let BVHNode::Branch { left, right, .. } = bvhn {
+        print_tree(f, depth + 1, left)?;
+        print_tree(f, depth + 1, right)?;
+    }
+    Ok(())
+}
+
+impl fmt::Display for BVH {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        writeln!(f, "Root")?;
+        print_tree(f, 1, &self.root)
+    }
+}
+
+impl Hit for BVH {
+    fn hit(&self, r: Ray, t_min: f32, t_max: f32) -> Option<HitRecord> {
+        self.root.hit(r, t_min, t_max)
+    }
+
+    fn bounding_box(&self, t_min: f32, t_max: f32) -> Option<AABB> {
+        self.root.bounding_box(t_min, t_max)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::aabb::AABB;
+    use crate::material::Lambertian;
+    use crate::material::Metal;
+    use crate::sphere::Sphere;
+    use crate::texture::ConstantTexture;
+    use crate::vec3::Vec3;
+
+    use super::*;
+
+    #[test]
+    fn bbox_two_spheres() {
+        let two_spheres_bvh = BVH::new(
+            vec![
+                Box::new(Sphere::new(
+                    Vec3::new(0., 0., 0.),
+                    0.5,
+                    Lambertian::new(ConstantTexture::new(Vec3::new(0.1, 0.2, 0.5))),
+                )),
+                Box::new(Sphere::new(
+                    Vec3::new(1., 0., 0.),
+                    0.5,
+                    Metal::new(Vec3::new(0.6, 0.6, 0.6), 0.2),
+                )),
+            ],
+            0.,
+            1.,
+        );
+        assert_eq!(
+            AABB::new(Vec3::new(-0.5, -0.5, -0.5), Vec3::new(1.5, 0.5, 0.5)),
+            two_spheres_bvh.bounding_box(0., 1.).unwrap(),
+            "BVH:\n{}",
+            two_spheres_bvh
+        );
+    }
+
+    #[test]
+    fn bbox_three_spheres() {
+        let three_spheres_bvh = BVH::new(
+            vec![
+                Box::new(Sphere::new(
+                    Vec3::new(0., 0., 0.),
+                    0.5,
+                    Lambertian::new(ConstantTexture::new(Vec3::new(0.1, 0.2, 0.5))),
+                )),
+                Box::new(Sphere::new(
+                    Vec3::new(1., 0., 0.),
+                    0.5,
+                    Metal::new(Vec3::new(0.6, 0.6, 0.6), 0.2),
+                )),
+                Box::new(Sphere::new(
+                    Vec3::new(0., 1., 0.),
+                    0.5,
+                    Metal::new(Vec3::new(0.6, 0.6, 0.6), 0.2),
+                )),
+            ],
+            0.,
+            1.,
+        );
+        assert_eq!(
+            AABB::new(Vec3::new(-0.5, -0.5, -0.5), Vec3::new(1.5, 1.5, 0.5)),
+            three_spheres_bvh.bounding_box(0., 1.).unwrap(),
+            "BVH:\n{}",
+            three_spheres_bvh
+        );
+    }
+}

rtiow/renderer/src/camera.rs

@@ -0,0 +1,82 @@
+use std::f32::consts::PI;
+
+use rand;
+use rand::Rng;
+
+use crate::ray::Ray;
+use crate::vec3::cross;
+use crate::vec3::Vec3;
+
+fn random_in_unit_disk() -> Vec3 {
+    let mut rng = rand::thread_rng();
+    let v = Vec3::new(1., 1., 0.);
+    loop {
+        let p = 2. * Vec3::new(rng.gen_range(0., 1.), rng.gen_range(0., 1.), 0.) - v;
+        if p.squared_length() < 1. {
+            return p;
+        }
+    }
+}
+
+pub struct Camera {
+    origin: Vec3,
+    lower_left_corner: Vec3,
+    horizontal: Vec3,
+    vertical: Vec3,
+    u: Vec3,
+    v: Vec3,
+    lens_radius: f32,
+    time_min: f32,
+    time_max: f32,
+}
+
+impl Camera {
+    // Parameters match the example C++ code.
+    #[allow(clippy::too_many_arguments)]
+    // vfov is top to bottom in degrees
+    pub fn new(
+        lookfrom: Vec3,
+        lookat: Vec3,
+        vup: Vec3,
+        vfov: f32,
+        aspect: f32,
+        aperture: f32,
+        focus_dist: f32,
+        time_min: f32,
+        time_max: f32,
+    ) -> Camera {
+        let theta = vfov * PI / 180.;
+        let half_height = (theta / 2.).tan();
+        let half_width = aspect * half_height;
+        let origin = lookfrom;
+        let w = (lookfrom - lookat).unit_vector();
+        let u = cross(vup, w).unit_vector();
+        let v = cross(w, u);
+        Camera {
+            lower_left_corner: origin
+                - half_width * focus_dist * u
+                - half_height * focus_dist * v
+                - focus_dist * w,
+            horizontal: 2. * half_width * focus_dist * u,
+            vertical: 2. * half_height * focus_dist * v,
+            origin,
+            u: cross(vup, w).unit_vector(),
+            v: cross(w, u),
+            lens_radius: aperture / 2.,
+            time_min,
+            time_max,
+        }
+    }
+
+    pub fn get_ray(&self, u: f32, v: f32) -> Ray {
+        let mut rng = rand::thread_rng();
+        let rd = self.lens_radius * random_in_unit_disk();
+        let offset = self.u * rd.x + self.v * rd.y;
+        let time = self.time_min + rng.gen_range(0., 1.) * (self.time_max - self.time_min);
+        Ray::new(
+            self.origin + offset,
+            self.lower_left_corner + self.horizontal * u + self.vertical * v - self.origin - offset,
+            time,
+        )
+    }
+}

rtiow/renderer/src/constant_medium.rs

@@ -0,0 +1,88 @@
+use std;
+
+use rand;
+use rand::Rng;
+
+use crate::aabb::AABB;
+use crate::hitable::Hit;
+use crate::hitable::HitRecord;
+use crate::material::Isotropic;
+use crate::ray::Ray;
+use crate::texture::Texture;
+use crate::vec3::Vec3;
+
+pub struct ConstantMedium<H, T>
+where
+    H: Hit,
+    T: Texture,
+{
+    density: f32,
+    material: Isotropic<T>,
+    hitable: H,
+}
+
+impl<H, T> ConstantMedium<H, T>
+where
+    H: Hit,
+    T: Texture,
+{
+    pub fn new(hitable: H, density: f32, texture: T) -> ConstantMedium<H, T>
+    where
+        T: Texture,
+    {
+        ConstantMedium {
+            density,
+            material: Isotropic::new(texture),
+            hitable,
+        }
+    }
+}
+
+impl<H, T> Hit for ConstantMedium<H, T>
+where
+    H: Hit,
+    T: Texture,
+{
+    fn hit(&self, r: Ray, t_min: f32, t_max: f32) -> Option<HitRecord> {
+        let mut rng = rand::thread_rng();
+        if let Some(mut rec1) = self.hitable.hit(r, std::f32::MIN, std::f32::MAX) {
+            if let Some(mut rec2) = self.hitable.hit(r, rec1.t + 0.001, std::f32::MAX) {
+                if rec1.t < t_min {
+                    rec1.t = t_min;
+                }
+                if rec2.t > t_max {
+                    rec2.t = t_max;
+                }
+                if rec1.t >= rec2.t {
+                    return None;
+                }
+                if rec1.t < 0. {
+                    rec1.t = 0.;
+                }
+                let distance_inside_boundary = (rec2.t - rec1.t) * r.direction.length();
+                let hit_distance = -(1. / self.density) * rng.gen_range::<f32>(0., 1.).ln();
+                if hit_distance < distance_inside_boundary {
+                    let t = rec1.t + hit_distance / r.direction.length();
+                    let normal = Vec3::new(
+                        rng.gen_range(0., 1.),
+                        rng.gen_range(0., 1.),
+                        rng.gen_range(0., 1.),
+                    )
+                    .unit_vector();
+                    return Some(HitRecord {
+                        t,
+                        p: r.point_at_parameter(t),
+                        normal,
+                        material: &self.material,
+                        uv: (0., 0.),
+                    });
+                }
+            }
+        }
+        None
+    }
+
+    fn bounding_box(&self, t_min: f32, t_max: f32) -> Option<AABB> {
+        self.hitable.bounding_box(t_min, t_max)
+    }
+}

rtiow/renderer/src/cuboid.rs

@@ -0,0 +1,90 @@
+use std::sync::Arc;
+
+use crate::aabb::AABB;
+use crate::flip_normals::FlipNormals;
+use crate::hitable::Hit;
+use crate::hitable::HitRecord;
+use crate::hitable_list::HitableList;
+use crate::material::Material;
+use crate::ray::Ray;
+use crate::rect::XYRect;
+use crate::rect::XZRect;
+use crate::rect::YZRect;
+use crate::vec3::Vec3;
+
+pub struct Cuboid {
+    p_min: Vec3,
+    p_max: Vec3,
+    walls: HitableList,
+}
+
+impl Cuboid {
+    // This clippy doesn't work right with Arc.
+    #[allow(clippy::needless_pass_by_value)]
+    pub fn new(p_min: Vec3, p_max: Vec3, material: Arc<dyn Material>) -> Cuboid {
+        Cuboid {
+            p_min,
+            p_max,
+            walls: HitableList::new(vec![
+                Box::new(XYRect::new(
+                    p_min.x,
+                    p_max.x,
+                    p_min.y,
+                    p_max.y,
+                    p_max.z,
+                    Arc::clone(&material),
+                )),
+                Box::new(FlipNormals::new(XYRect::new(
+                    p_min.x,
+                    p_max.x,
+                    p_min.y,
+                    p_max.y,
+                    p_min.z,
+                    Arc::clone(&material),
+                ))),
+                Box::new(XZRect::new(
+                    p_min.x,
+                    p_max.x,
+                    p_min.z,
+                    p_max.z,
+                    p_max.y,
+                    Arc::clone(&material),
+                )),
+                Box::new(FlipNormals::new(XZRect::new(
+                    p_min.x,
+                    p_max.x,
+                    p_min.z,
+                    p_max.z,
+                    p_min.y,
+                    Arc::clone(&material),
+                ))),
+                Box::new(YZRect::new(
+                    p_min.y,
+                    p_max.y,
+                    p_min.z,
+                    p_max.z,
+                    p_max.x,
+                    Arc::clone(&material),
+                )),
+                Box::new(FlipNormals::new(YZRect::new(
+                    p_min.y,
+                    p_max.y,
+                    p_min.z,
+                    p_max.z,
+                    p_min.x,
+                    Arc::clone(&material),
+                ))),
+            ]),
+        }
+    }
+}
+
+impl Hit for Cuboid {
+    fn hit(&self, r: Ray, t_min: f32, t_max: f32) -> Option<HitRecord> {
+        self.walls.hit(r, t_min, t_max)
+    }
+
+    fn bounding_box(&self, _t_min: f32, _t_max: f32) -> Option<AABB> {
+        Some(AABB::new(self.p_min, self.p_max))
+    }
+}

rtiow/renderer/src/flip_normals.rs

@@ -0,0 +1,39 @@
+use crate::aabb::AABB;
+use crate::hitable::Hit;
+use crate::hitable::HitRecord;
+use crate::ray::Ray;
+
+pub struct FlipNormals<H>
+where
+    H: Hit,
+{
+    hitable: H,
+}
+
+impl<H> FlipNormals<H>
+where
+    H: Hit,
+{
+    pub fn new(hitable: H) -> FlipNormals<H> {
+        FlipNormals { hitable }
+    }
+}
+
+impl<H> Hit for FlipNormals<H>
+where
+    H: Hit,
+{
+    fn hit(&self, r: Ray, t_min: f32, t_max: f32) -> Option<HitRecord> {
+        if let Some(rec) = self.hitable.hit(r, t_min, t_max) {
+            return Some(HitRecord {
+                normal: -rec.normal,
+                ..rec
+            });
+        };
+        None
+    }
+
+    fn bounding_box(&self, t_min: f32, t_max: f32) -> Option<AABB> {
+        self.hitable.bounding_box(t_min, t_max)
+    }
+}

rtiow/renderer/src/hitable.rs

@@ -0,0 +1,28 @@
+use std::sync::Arc;
+
+use crate::aabb::AABB;
+use crate::material::Material;
+use crate::ray::Ray;
+use crate::vec3::Vec3;
+
+pub struct HitRecord<'m> {
+    pub t: f32,
+    pub uv: (f32, f32),
+    pub p: Vec3,
+    pub normal: Vec3,
+    pub material: &'m dyn Material,
+}
+
+pub trait Hit: Send + Sync {
+    fn hit(&self, r: Ray, t_min: f32, t_max: f32) -> Option<HitRecord>;
+    fn bounding_box(&self, t_min: f32, t_max: f32) -> Option<AABB>;
+}
+
+impl Hit for Arc<dyn Hit> {
+    fn hit(&self, r: Ray, t_min: f32, t_max: f32) -> Option<HitRecord> {
+        (**self).hit(r, t_min, t_max)
+    }
+    fn bounding_box(&self, t_min: f32, t_max: f32) -> Option<AABB> {
+        (**self).bounding_box(t_min, t_max)
+    }
+}

rtiow/renderer/src/hitable_list.rs

@@ -0,0 +1,48 @@
+use std;
+
+use crate::aabb::surrounding_box;
+use crate::aabb::AABB;
+use crate::hitable::Hit;
+use crate::hitable::HitRecord;
+use crate::ray::Ray;
+use crate::vec3::Vec3;
+
+#[derive(Default)]
+pub struct HitableList {
+    list: Vec<Box<dyn Hit>>,
+}
+
+impl HitableList {
+    pub fn new(list: Vec<Box<dyn Hit>>) -> HitableList {
+        HitableList { list }
+    }
+}
+
+impl Hit for HitableList {
+    fn hit(&self, r: Ray, t_min: f32, t_max: f32) -> Option<HitRecord> {
+        let mut min_hit = None;
+        let mut closest_so_far = t_max;
+        for hitable in &self.list {
+            if let Some(h) = hitable.hit(r, t_min, closest_so_far) {
+                closest_so_far = h.t;
+                min_hit = Some(h);
+            }
+        }
+        min_hit
+    }
+
+    fn bounding_box(&self, t_min: f32, t_max: f32) -> Option<AABB> {
+        // TODO(wathiede): I don't understand the version from the book, this implementation
+        // returns a superset of all bounding boxes.
+        let super_box = AABB::new(
+            Vec3::new(std::f32::MAX, std::f32::MAX, std::f32::MAX),
+            Vec3::new(std::f32::MIN, std::f32::MIN, std::f32::MIN),
+        );
+        Some(self.list.iter().fold(super_box, |acc, hitable| {
+            match hitable.bounding_box(t_min, t_max) {
+                Some(bbox) => surrounding_box(&acc, &bbox),
+                None => acc,
+            }
+        }))
+    }
+}

rtiow/renderer/src/human.rs

@@ -0,0 +1,227 @@
+#![allow(dead_code)]
+//! From https://raw.githubusercontent.com/BobGneu/human-format-rs/master/src/lib.rs
+//! `human` provides facilitates creating a formatted string, converting between numbers that are beyond typical
+//! needs for humans into a simpler string that conveys the gist of the meaning of the number.
+//!
+//! Print some human readable strings
+//!
+//! ```rust
+//! use rtiow::human;
+//!
+//! // "1.00 k"
+//! let tmpStr = human::Formatter::new()
+//!     .format(1000.0);
+//! # assert_eq!(tmpStr, "1.00 k");
+//!
+//! // "1.00 M"
+//! let tmpStr2 = human::Formatter::new()
+//!     .format(1000000.0);
+//! # assert_eq!(tmpStr2, "1.00 M");
+//!
+//! // "1.00 B"
+//! let tmpStr3 = human::Formatter::new()
+//!     .format(1000000000.0);
+//! # assert_eq!(tmpStr3, "1.00 B");
+//! ```
+//!
+//! If you are so inspired you can even try playing with units and customizing your `Scales`
+//!
+//! For more examples you should review the examples on github: [tests/demo.rs](https://github.com/BobGneu/human-format-rs/blob/master/tests/demo.rs)
+//!
+
+#[derive(Debug)]
+struct ScaledValue {
+    value: f32,
+    suffix: String,
+}
+
+/// Entry point to the lib. Use this to handle your formatting needs.
+#[derive(Debug)]
+pub struct Formatter {
+    decimals: usize,
+    separator: String,
+    scales: Scales,
+    forced_units: String,
+    forced_suffix: String,
+}
+
+/// Provide a customized scaling scheme for your own modeling.
+#[derive(Debug)]
+pub struct Scales {
+    base: u32,
+    suffixes: Vec<String>,
+}
+
+impl Formatter {
+    /// Initializes a new `Formatter` with default values.
+    pub fn new() -> Self {
+        Formatter {
+            decimals: 2,
+            separator: " ".to_owned(),
+            scales: Scales::si(),
+            forced_units: "".to_owned(),
+            forced_suffix: "".to_owned(),
+        }
+    }
+
+    /// Sets the decimals value for formatting the string.
+    pub fn with_decimals(&mut self, decimals: usize) -> &mut Self {
+        self.decimals = decimals;
+
+        self
+    }
+
+    /// Sets the separator value for formatting the string.
+    pub fn with_separator(&mut self, separator: &str) -> &mut Self {
+        self.separator = separator.to_owned();
+
+        self
+    }
+
+    /// Sets the scales value.
+    pub fn with_scales(&mut self, scales: Scales) -> &mut Self {
+        self.scales = scales;
+
+        self
+    }
+
+    /// Sets the units value.
+    pub fn with_units(&mut self, units: &str) -> &mut Self {
+        self.forced_units = units.to_owned();
+
+        self
+    }
+
+    /// Sets the expected suffix value.
+    pub fn with_suffix(&mut self, suffix: &str) -> &mut Self {
+        self.forced_suffix = suffix.to_owned();
+
+        self
+    }
+
+    /// Formats the number into a string
+    pub fn format(&self, value: f64) -> String {
+        if value < 0.0 {
+            return format!("-{}", self.format(value * -1.0));
+        }
+
+        let scaled_value = self.scales.to_scaled_value(value);
+
+        format!(
+            "{:.width$}{}{}{}",
+            scaled_value.value,
+            self.separator,
+            scaled_value.suffix,
+            self.forced_units,
+            width = self.decimals
+        )
+    }
+
+    /// Parse a string back into a float value.
+    pub fn parse(&self, value: &str) -> f64 {
+        let v: Vec<&str> = value.split(&self.separator).collect();
+
+        let result = v.get(0).unwrap().parse::<f64>().unwrap();
+
+        let mut suffix = v.get(1).unwrap().to_string();
+        let new_len = suffix.len() - self.forced_units.len();
+
+        suffix.truncate(new_len);
+
+        let magnitude_multiplier = self.scales.get_magnitude_multipler(&suffix);
+
+        (result * magnitude_multiplier)
+    }
+}
+
+impl Scales {
+    /// Instantiates a new `Scales` with SI keys
+    pub fn new() -> Self {
+        Scales::si()
+    }
+
+    /// Instantiates a new `Scales` with SI keys
+    pub fn si() -> Self {
+        Scales {
+            base: 1000,
+            suffixes: vec![
+                "".to_owned(),
+                "k".to_owned(),
+                "M".to_owned(),
+                "B".to_owned(),
+                "T".to_owned(),
+                "P".to_owned(),
+                "E".to_owned(),
+                "Z".to_owned(),
+                "Y".to_owned(),
+            ],
+        }
+    }
+
+    /// Instantiates a new `Scales` with Binary keys
+    pub fn binary() -> Self {
+        Scales {
+            base: 1000,
+            suffixes: vec![
+                "".to_owned(),
+                "ki".to_owned(),
+                "Mi".to_owned(),
+                "Gi".to_owned(),
+                "Ti".to_owned(),
+                "Pi".to_owned(),
+                "Ei".to_owned(),
+                "Zi".to_owned(),
+                "Yi".to_owned(),
+            ],
+        }
+    }
+
+    /// Sets the base for the `Scales`
+    pub fn with_base(&mut self, base: u32) -> &mut Self {
+        self.base = base;
+
+        self
+    }
+
+    /// Sets the suffixes listing appropriately
+    pub fn with_suffixes(&mut self, suffixes: Vec<&str>) -> &mut Self {
+        self.suffixes = Vec::new();
+
+        for suffix in suffixes {
+            // This should be to_owned to be clear about intent.
+            // https://users.rust-lang.org/t/to-string-vs-to-owned-for-string-literals/1441/6
+            self.suffixes.push(suffix.to_owned());
+        }
+
+        self
+    }
+
+    fn get_magnitude_multipler(&self, value: &str) -> f64 {
+        for ndx in 0..self.suffixes.len() {
+            if value == self.suffixes[ndx] {
+                return self.base.pow(ndx as u32) as f64;
+            }
+        }
+
+        return 0.0;
+    }
+
+    fn to_scaled_value(&self, value: f64) -> ScaledValue {
+        let mut index: usize = 0;
+        let mut _value: f64 = value;
+
+        loop {
+            if _value < (self.base as f64) {
+                break;
+            }
+
+            _value /= self.base as f64;
+            index += 1;
+        }
+
+        ScaledValue {
+            value: (value / self.base.pow((index) as u32) as f64) as f32,
+            suffix: self.suffixes[index].to_owned(),
+        }
+    }
+}

rtiow/renderer/src/kdtree.rs

@@ -0,0 +1,191 @@
+use std::fmt;
+
+use log::info;
+
+use crate::aabb::surrounding_box;
+use crate::aabb::AABB;
+use crate::hitable::Hit;
+use crate::hitable::HitRecord;
+use crate::ray::Ray;
+
+pub enum KDTree {
+    Leaf(Box<dyn Hit>),
+    Branch {
+        left: Box<KDTree>,
+        right: Box<KDTree>,
+        bbox: Option<AABB>,
+    },
+}
+
+// Return the first element from the vector, which should be the only element.
+// TODO(wathiede): we really want a .first_into() (.first() doesn't work because it
+// returns a reference.)
+fn vec_first_into<T>(v: Vec<T>) -> T {
+    if v.len() != 1 {
+        panic!(format!(
+            "vec_first_into called for vector length != 1, length {}",
+            v.len()
+        ));
+    }
+    v.into_iter().next().unwrap()
+}
+
+fn vec_split_into<T>(v: Vec<T>, offset: usize) -> (Vec<T>, Vec<T>) {
+    let mut left_half = Vec::new();
+    let mut right_half = Vec::new();
+    v.into_iter().enumerate().for_each(|(i, h)| {
+        if i < offset {
+            left_half.push(h);
+        } else {
+            right_half.push(h);
+        }
+    });
+    (left_half, right_half)
+}
+
+impl KDTree {
+    pub fn new(l: Vec<Box<dyn Hit>>, t_min: f32, t_max: f32) -> KDTree {
+        if l.is_empty() {
+            panic!("Attempt to build k-d tree with no Hit objects");
+        }
+
+        if l.len() == 1 {
+            return KDTree::Leaf(vec_first_into(l));
+        }
+
+        if l.len() == 2 {
+            let (left_vec, right_vec) = vec_split_into(l, 1);
+            let left = vec_first_into(left_vec);
+            let right = vec_first_into(right_vec);
+            let bbox = surrounding_box(
+                &left.bounding_box(t_min, t_max).unwrap(),
+                &right.bounding_box(t_min, t_max).unwrap(),
+            );
+            return KDTree::Branch {
+                left: Box::new(KDTree::Leaf(left)),
+                right: Box::new(KDTree::Leaf(right)),
+                bbox: Some(bbox),
+            };
+        }
+        let bbox = l[0].bounding_box(t_min, t_max).unwrap();
+        let mut mid_point = bbox.mid_point();
+        let bbox = l[1..].iter().fold(bbox, |acc, h| {
+            let new_bbox = &h.bounding_box(t_min, t_max).unwrap();
+            mid_point = mid_point + new_bbox.mid_point();
+            surrounding_box(&acc, new_bbox)
+        });
+        mid_point = mid_point / l.len() as f32;
+        let axis = bbox.longest_axis();
+        let mut left_half = Vec::new();
+        let mut right_half = Vec::new();
+        match axis {
+            0 => l.into_iter().for_each(|h| {
+                if h.bounding_box(t_min, t_max).unwrap().mid_point().x < mid_point.x {
+                    left_half.push(h);
+                } else {
+                    right_half.push(h);
+                }
+            }),
+            1 => l.into_iter().for_each(|h| {
+                if h.bounding_box(t_min, t_max).unwrap().mid_point().y < mid_point.y {
+                    left_half.push(h);
+                } else {
+                    right_half.push(h);
+                }
+            }),
+            2 => l.into_iter().for_each(|h| {
+                if h.bounding_box(t_min, t_max).unwrap().mid_point().z < mid_point.z {
+                    left_half.push(h);
+                } else {
+                    right_half.push(h);
+                }
+            }),
+            _ => panic!("Unreachable"),
+        };
+        KDTree::Branch {
+            left: Box::new(KDTree::new(left_half, t_min, t_max)),
+            right: Box::new(KDTree::new(right_half, t_min, t_max)),
+            bbox: Some(bbox),
+        }
+    }
+
+    fn volume(&self) -> f32 {
+        let bbox = self.bounding_box(0., 0.).unwrap();
+        (bbox.min().x - bbox.max().x).abs()
+            * (bbox.min().y - bbox.max().y).abs()
+            * (bbox.min().z - bbox.max().z).abs()
+    }
+}
+
+fn print_tree(f: &mut fmt::Formatter, depth: usize, kdt: &KDTree) -> fmt::Result {
+    let vol = kdt.volume();
+    write!(f, "{:8.2}{}", vol, " ".repeat(depth * 2))?;
+    match kdt {
+        KDTree::Leaf(ref hit) => writeln!(
+            f,
+            "Leaf: {}",
+            hit.bounding_box(0., 0.)
+                .map_or("NO BBOX".to_owned(), |bb| bb.to_string())
+        )?,
+        KDTree::Branch { bbox, .. } => writeln!(
+            f,
+            "Branch: {}",
+            // TODO(wathiede): removing this .clone() results in a complaint about moving out
+            // of a borrow.
+            bbox.clone()
+                .map_or("NO BBOX".to_owned(), |bb| bb.to_string())
+        )?,
+    }
+    if let KDTree::Branch { left, right, .. } = kdt {
+        print_tree(f, depth + 1, left)?;
+        print_tree(f, depth + 1, right)?;
+    }
+    Ok(())
+}
+
+impl fmt::Display for KDTree {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        writeln!(f, "kd-tree")?;
+        print_tree(f, 1, &self)
+    }
+}
+impl Hit for KDTree {
+    fn hit(&self, r: Ray, t_min: f32, t_max: f32) -> Option<HitRecord> {
+        match self.bounding_box(t_min, t_max) {
+            Some(bbox) => {
+                if !bbox.hit(r, t_min, t_max) {
+                    return None;
+                }
+            }
+            None => {
+                info!("KDTree::hit no bbox: {:?}", r);
+                return None;
+            }
+        }
+        match self {
+            KDTree::Leaf(ref hit) => hit.hit(r, t_min, t_max),
+            KDTree::Branch { left, right, bbox } => match bbox {
+                None => None,
+                Some(_bbox) => match (left.hit(r, t_min, t_max), right.hit(r, t_min, t_max)) {
+                    (Some(hit_left), Some(hit_right)) => {
+                        if hit_left.t < hit_right.t {
+                            Some(hit_left)
+                        } else {
+                            Some(hit_right)
+                        }
+                    }
+                    (Some(hit_left), None) => Some(hit_left),
+                    (None, Some(hit_right)) => Some(hit_right),
+                    (None, None) => None,
+                },
+            },
+        }
+    }
+
+    fn bounding_box(&self, t_min: f32, t_max: f32) -> Option<AABB> {
+        match self {
+            KDTree::Leaf(ref hit) => hit.bounding_box(t_min, t_max),
+            KDTree::Branch { bbox, .. } => bbox.clone(),
+        }
+    }
+}

rtiow/renderer/src/lib.rs

@@ -0,0 +1,23 @@
+pub mod aabb;
+pub mod bvh;
+pub mod camera;
+pub mod constant_medium;
+pub mod cuboid;
+pub mod flip_normals;
+pub mod hitable;
+pub mod hitable_list;
+pub mod human;
+pub mod kdtree;
+pub mod material;
+pub mod moving_sphere;
+pub mod noise;
+pub mod output;
+pub mod ray;
+pub mod rect;
+pub mod renderer;
+pub mod rotate;
+pub mod scenes;
+pub mod sphere;
+pub mod texture;
+pub mod translate;
+pub mod vec3;

rtiow/renderer/src/material.rs

@@ -0,0 +1,274 @@
+use std::sync::Arc;
+
+use rand;
+use rand::Rng;
+
+use crate::hitable::HitRecord;
+use crate::ray::Ray;
+use crate::texture::Texture;
+use crate::vec3::dot;
+use crate::vec3::Vec3;
+
+fn random_in_unit_sphere() -> Vec3 {
+    let mut rng = rand::thread_rng();
+    let v = Vec3::new(1., 1., 1.);
+    loop {
+        let p =
+            2. * Vec3::new(
+                rng.gen_range(0., 1.),
+                rng.gen_range(0., 1.),
+                rng.gen_range(0., 1.),
+            ) - v;
+        if p.squared_length() < 1. {
+            return p;
+        }
+    }
+}
+
+#[derive(Default)]
+pub struct ScatterResponse {
+    pub scattered: Ray,
+    pub attenutation: Vec3,
+    pub reflected: bool,
+}
+
+pub trait Material: Send + Sync {
+    fn scatter(&self, r_in: &Ray, rec: &HitRecord) -> ScatterResponse;
+    fn emitted(&self, _u: f32, _v: f32, _p: Vec3) -> Vec3 {
+        Vec3::new(0., 0., 0.)
+    }
+}
+
+impl Material for Arc<dyn Material> {
+    fn scatter(&self, r_in: &Ray, rec: &HitRecord) -> ScatterResponse {
+        (**self).scatter(r_in, rec)
+    }
+    fn emitted(&self, u: f32, v: f32, p: Vec3) -> Vec3 {
+        (**self).emitted(u, v, p)
+    }
+}
+
+impl Material for Box<dyn Material> {
+    fn scatter(&self, r_in: &Ray, rec: &HitRecord) -> ScatterResponse {
+        (**self).scatter(r_in, rec)
+    }
+    fn emitted(&self, u: f32, v: f32, p: Vec3) -> Vec3 {
+        (**self).emitted(u, v, p)
+    }
+}
+
+pub struct Isotropic<T>
+where
+    T: Texture,
+{
+    albedo: T,
+}
+
+impl<T> Isotropic<T>
+where
+    T: Texture,
+{
+    pub fn new(texture: T) -> Isotropic<T> {
+        Isotropic { albedo: texture }
+    }
+}
+
+impl<T> Material for Isotropic<T>
+where
+    T: Texture,
+{
+    fn scatter(&self, _r_in: &Ray, rec: &HitRecord) -> ScatterResponse {
+        let (u, v) = rec.uv;
+        ScatterResponse {
+            attenutation: self.albedo.value(u, v, rec.p),
+            scattered: Ray::new(rec.p, random_in_unit_sphere(), 0.),
+            reflected: true,
+        }
+    }
+}
+
+pub struct Lambertian<T>
+where
+    T: Texture,
+{
+    albedo: T,
+}
+
+impl<T> Lambertian<T>
+where
+    T: Texture,
+{
+    pub fn new(texture: T) -> Lambertian<T> {
+        Lambertian { albedo: texture }
+    }
+}
+
+impl<T> Material for Lambertian<T>
+where
+    T: Texture,
+{
+    fn scatter(&self, r_in: &Ray, rec: &HitRecord) -> ScatterResponse {
+        let target = rec.p + rec.normal + random_in_unit_sphere();
+        let (u, v) = rec.uv;
+        ScatterResponse {
+            attenutation: self.albedo.value(u, v, rec.p),
+            scattered: Ray::new(rec.p, target - rec.p, r_in.time),
+            reflected: true,
+        }
+    }
+}
+
+pub struct Metal {
+    albedo: Vec3,
+    fuzzy: f32,
+}
+
+fn reflect(v: Vec3, n: Vec3) -> Vec3 {
+    v - 2. * dot(v, n) * n
+}
+
+impl Metal {
+    pub fn new<V>(albedo: V, fuzzy: f32) -> Metal
+    where
+        V: Into<Vec3>,
+    {
+        let fuzzy = fuzzy.min(1.);
+        Metal {
+            albedo: albedo.into(),
+            fuzzy,
+        }
+    }
+}
+
+impl Material for Metal {
+    fn scatter(&self, r_in: &Ray, rec: &HitRecord) -> ScatterResponse {
+        let reflected = reflect(r_in.direction.unit_vector(), rec.normal);
+        let scattered = Ray::new(
+            rec.p,
+            reflected + self.fuzzy * random_in_unit_sphere(),
+            r_in.time,
+        );
+        ScatterResponse {
+            scattered,
+            attenutation: self.albedo,
+            reflected: dot(scattered.direction, rec.normal) > 0.,
+        }
+    }
+}
+
+fn refract(v: Vec3, n: Vec3, ni_over_nt: f32) -> Option<Vec3> {
+    let uv = v.unit_vector();
+    let dt = dot(uv, n);
+    let discriminant = 1. - ni_over_nt * ni_over_nt * (1. - dt * dt);
+    if discriminant > 0. {
+        return Some(ni_over_nt * (uv - n * dt) - n * discriminant.sqrt());
+    }
+    None
+}
+
+fn schlick(cosine: f32, ref_idx: f32) -> f32 {
+    let mut r0 = (1. - ref_idx) / (1. + ref_idx);
+    r0 = r0 * r0;
+    r0 + (1. - r0) * (1. - cosine).powf(5.)
+}
+
+pub struct Dielectric {
+    ref_idx: f32,
+}
+
+impl Dielectric {
+    pub fn new(ref_idx: f32) -> Dielectric {
+        Dielectric { ref_idx }
+    }
+}
+
+impl Material for Dielectric {
+    fn scatter(&self, r_in: &Ray, rec: &HitRecord) -> ScatterResponse {
+        let reflected = reflect(r_in.direction, rec.normal);
+        let (outward_normal, ni_over_nt, cosine) = if dot(r_in.direction, rec.normal) > 0. {
+            (
+                -rec.normal,
+                self.ref_idx,
+                self.ref_idx * dot(r_in.direction, rec.normal) / r_in.direction.length(),
+            )
+        } else {
+            (
+                rec.normal,
+                1. / self.ref_idx,
+                -dot(r_in.direction, rec.normal) / r_in.direction.length(),
+            )
+        };
+        let scattered = if let Some(refracted) = refract(r_in.direction, outward_normal, ni_over_nt)
+        {
+            let mut rng = rand::thread_rng();
+            if rng.gen_range(0., 1.) < schlick(cosine, self.ref_idx) {
+                Ray::new(rec.p, reflected, r_in.time)
+            } else {
+                Ray::new(rec.p, refracted, r_in.time)
+            }
+        } else {
+            Ray::new(rec.p, reflected, r_in.time)
+        };
+
+        ScatterResponse {
+            attenutation: Vec3::new(1., 1., 1.),
+            scattered,
+            reflected: true,
+        }
+    }
+}
+
+pub struct DiffuseLight<T>
+where
+    T: Texture,
+{
+    emit: T,
+}
+
+impl<T> DiffuseLight<T>
+where
+    T: Texture,
+{
+    pub fn new(emit: T) -> DiffuseLight<T> {
+        DiffuseLight { emit }
+    }
+}
+
+impl<T> Material for DiffuseLight<T>
+where
+    T: Texture,
+{
+    fn scatter(&self, _r_in: &Ray, _rec: &HitRecord) -> ScatterResponse {
+        ScatterResponse {
+            scattered: Default::default(),
+            attenutation: Default::default(),
+            reflected: false,
+        }
+    }
+
+    fn emitted(&self, u: f32, v: f32, p: Vec3) -> Vec3 {
+        self.emit.value(u, v, p)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::texture::ConstantTexture;
+
+    #[test]
+    fn arc_material() {
+        let white: Arc<dyn Material> =
+            Arc::new(Lambertian::new(ConstantTexture::new([0.73, 0.73, 0.73])));
+
+        fn material_fn<M>(m: M)
+        where
+            M: Material,
+        {
+            let _ = m;
+        }
+
+        material_fn(Arc::clone(&white));
+        material_fn(Arc::clone(&white));
+    }
+}

rtiow/renderer/src/moving_sphere.rs

@@ -0,0 +1,101 @@
+use crate::aabb::surrounding_box;
+use crate::aabb::AABB;
+use crate::hitable::Hit;
+use crate::hitable::HitRecord;
+use crate::material::Material;
+use crate::ray::Ray;
+use crate::sphere::get_sphere_uv;
+use crate::vec3::dot;
+use crate::vec3::Vec3;
+
+pub struct MovingSphere<M>
+where
+    M: Material,
+{
+    center0: Vec3,
+    center1: Vec3,
+    radius: f32,
+    material: M,
+    time0: f32,
+    time1: f32,
+}
+
+impl<M> MovingSphere<M>
+where
+    M: Material,
+{
+    pub fn new(
+        center0: Vec3,
+        center1: Vec3,
+        radius: f32,
+        time0: f32,
+        time1: f32,
+        material: M,
+    ) -> MovingSphere<M> {
+        MovingSphere {
+            center0,
+            center1,
+            radius,
+            material,
+            time0,
+            time1,
+        }
+    }
+    fn center(&self, time: f32) -> Vec3 {
+        self.center0
+            + ((time - self.time0) / (self.time1 - self.time0)) * (self.center1 - self.center0)
+    }
+}
+
+impl<M> Hit for MovingSphere<M>
+where
+    M: Material,
+{
+    fn hit(&self, r: Ray, t0: f32, t1: f32) -> Option<HitRecord> {
+        let oc = r.origin - self.center(r.time);
+        let a = dot(r.direction, r.direction);
+        let b = dot(oc, r.direction);
+        let c = dot(oc, oc) - self.radius * self.radius;
+        let discriminant = b * b - a * c;
+        if discriminant > 0. {
+            let temp = (-b - (b * b - a * c).sqrt()) / a;
+            if temp < t1 && temp > t0 {
+                let point = r.point_at_parameter(temp);
+                let uv = get_sphere_uv((point - self.center(r.time)) / self.radius);
+                return Some(HitRecord {
+                    t: temp,
+                    uv,
+                    p: point,
+                    normal: (point - self.center(r.time)) / self.radius,
+                    material: &self.material,
+                });
+            }
+            let temp = (-b + (b * b - a * c).sqrt()) / a;
+            if temp < t1 && temp > t0 {
+                let point = r.point_at_parameter(temp);
+                let uv = get_sphere_uv((point - self.center(r.time)) / self.radius);
+                return Some(HitRecord {
+                    t: temp,
+                    uv,
+                    p: point,
+                    normal: (point - self.center(r.time)) / self.radius,
+                    material: &self.material,
+                });
+            }
+        }
+        None
+    }
+
+    fn bounding_box(&self, _t_min: f32, _t_max: f32) -> Option<AABB> {
+        let t_min_bb = AABB::new(
+            self.center0 - Vec3::new(self.radius, self.radius, self.radius),
+            self.center0 + Vec3::new(self.radius, self.radius, self.radius),
+        );
+
+        let t_max_bb = AABB::new(
+            self.center1 - Vec3::new(self.radius, self.radius, self.radius),
+            self.center1 + Vec3::new(self.radius, self.radius, self.radius),
+        );
+        Some(surrounding_box(&t_min_bb, &t_max_bb))
+    }
+}

rtiow/renderer/src/noise/lode.rs

@@ -0,0 +1,68 @@
+use log::trace;
+/// Implements the concepts from https://lodev.org/cgtutor/randomnoise.html
+use rand;
+
+use crate::noise::NoiseSource;
+use crate::vec3::Vec3;
+
+const NOISE_SIZE: usize = 128;
+pub struct Lode {
+    // Using fixed array causes stack overflow.
+    noise: Vec<Vec<Vec<f32>>>, //[[[f32; NOISE_SIZE]; NOISE_SIZE]; NOISE_SIZE],
+}
+
+impl Lode {
+    pub fn new<R>(rng: &mut R) -> Lode
+    where
+        R: rand::Rng,
+    {
+        let mut noise = vec![vec![vec![0.; NOISE_SIZE]; NOISE_SIZE]; NOISE_SIZE];
+        // Squelch warning about only being used to index, as this way reads more consistently.
+        #[allow(clippy::needless_range_loop)]
+        for x in 0..NOISE_SIZE {
+            for y in 0..NOISE_SIZE {
+                for z in 0..NOISE_SIZE {
+                    noise[x][y][z] = rng.gen_range(0., 1.);
+                }
+            }
+        }
+        Lode { noise }
+    }
+}
+
+impl NoiseSource for Lode {
+    fn value(&self, p: Vec3) -> f32 {
+        // Fractional part of vector components
+        let x = p.x - p.x.floor();
+        let y = p.y - p.y.floor();
+        let z = p.z - p.z.floor();
+
+        // Wrap around the arrays
+        let x1 = (p.x.floor() as usize + NOISE_SIZE) % NOISE_SIZE;
+        let y1 = (p.y.floor() as usize + NOISE_SIZE) % NOISE_SIZE;
+        let z1 = (p.z.floor() as usize + NOISE_SIZE) % NOISE_SIZE;
+
+        // Neighbor values
+        let x2 = (x1 as usize + NOISE_SIZE - 1) % NOISE_SIZE;
+        let y2 = (y1 as usize + NOISE_SIZE - 1) % NOISE_SIZE;
+        let z2 = (z1 as usize + NOISE_SIZE - 1) % NOISE_SIZE;
+
+        trace!(target: "noise", "p {}", p);
+        trace!(target: "noise", "x {:.2} y {:.2} z {:.2}", x, y, z);
+        trace!(target: "noise", "x1 {:.2} y1 {:.2} z1 {:.2}", x1, y1, z1);
+        trace!(target: "noise", "x2 {:.2} y2 {:.2} z2 {:.2}", x2, y2, z2);
+        let mut value = 0.;
+        // Smooth the noise with bilinear interpolation.  Completely untested
+        value += x * y * z * self.noise[x1][y1][z1];
+        value += (1. - x) * y * z * self.noise[x2][y1][z1];
+        value += x * (1. - y) * z * self.noise[x1][y2][z1];
+        value += x * y * (1. - z) * self.noise[x1][y1][z2];
+        value += (1. - x) * (1. - y) * z * self.noise[x2][y2][z1];
+        value += x * (1. - y) * (1. - z) * self.noise[x1][y2][z2];
+        value += (1. - x) * y * (1. - z) * self.noise[x2][y1][z2];
+        value += (1. - x) * (1. - y) * (1. - z) * self.noise[x2][y2][z2];
+
+        trace!(target: "noise", "luma {}", value);
+        value
+    }
+}

rtiow/renderer/src/noise/mod.rs

@@ -0,0 +1,96 @@
+pub mod lode;
+pub mod perlin;
+
+use std::f32::consts::PI;
+
+use serde_derive::Deserialize;
+
+use crate::vec3::Vec3;
+
+pub trait NoiseSource: Send + Sync {
+    /// value returns noise on the interval [0., 1.).
+    fn value(&self, p: Vec3) -> f32;
+
+    fn marble(&self, p: Vec3, period: Vec3, power: f32, size: usize, scale: f32) -> f32 {
+        let p = p / scale;
+        // TODO(wathiede): can't understand why 255 works for perlin and lode, maybe it's near 360
+        // degrees and interacts with the sine function?
+        let xyz_value = p.x * period.x / 255.
+            + p.y * period.y / 255.
+            + p.z * period.z / 255.
+            + power * self.turbulence(p, size);
+        (xyz_value * PI).sin().abs()
+    }
+
+    fn turbulence(&self, p: Vec3, factor: usize) -> f32 {
+        let mut value = 0.;
+        let initial_factor = factor;
+        let mut factor = factor;
+
+        while factor >= 1 {
+            value += self.value(p / factor as f32) * factor as f32;
+            factor /= 2;
+        }
+        0.5 * value / initial_factor as f32
+    }
+
+    fn scaled(&self, p: Vec3, scale: f32) -> f32 {
+        let p = p / scale;
+        self.value(p)
+    }
+}
+
+impl NoiseSource for Box<dyn NoiseSource> {
+    fn value(&self, p: Vec3) -> f32 {
+        (**self).value(p)
+    }
+}
+
+#[derive(Copy, Clone, Debug, Deserialize)]
+#[serde(tag = "type")]
+pub enum NoiseType {
+    Scale(f32),
+    Turbulence(usize),
+    Marble {
+        period: Vec3,
+        power: f32,
+        size: usize,
+        scale: f32,
+    },
+}
+
+impl NoiseType {
+    pub fn to_url(&self) -> String {
+        match &self {
+            NoiseType::Scale(scale) => format!("scale/{}", scale),
+            NoiseType::Turbulence(turbulence) => format!("turbulence/{}", turbulence),
+            NoiseType::Marble {
+                period,
+                power,
+                size,
+                scale,
+            } => format!(
+                "marble/period/{},{},{}/power/{}/size/{}/scale/{}",
+                period.x, period.y, period.z, power, size, scale
+            ),
+        }
+    }
+
+    pub fn parameters(&self) -> Vec<(&str, String)> {
+        match &self {
+            NoiseType::Scale(scale) => vec![("Scale", scale.to_string())],
+            NoiseType::Turbulence(turbulence) => vec![("Turbulence", turbulence.to_string())],
+            NoiseType::Marble {
+                period,
+                power,
+                size,
+                scale,
+            } => vec![
+                ("Period", period.to_string()),
+                ("Power", power.to_string()),
+                ("Size", size.to_string()),
+                ("Scale", scale.to_string()),
+            ],
+        }
+    }
+}

rtiow/renderer/src/noise/perlin.rs

@@ -0,0 +1,152 @@
+// There are many math functions in this file, so we allow single letter variable names.
+#![allow(clippy::many_single_char_names)]
+use log::trace;
+use rand::Rng;
+
+use crate::noise::NoiseSource;
+use crate::vec3::dot;
+use crate::vec3::Vec3;
+
+pub struct Perlin {
+    ran_vec: Vec<Vec3>,
+    perm_x: Vec<usize>,
+    perm_y: Vec<usize>,
+    perm_z: Vec<usize>,
+}
+
+fn perlin_generate<R>(rng: &mut R) -> Vec<Vec3>
+where
+    R: Rng,
+{
+    (0..256)
+        .map(|_| {
+            Vec3::new(
+                rng.gen_range(-1., 1.),
+                rng.gen_range(-1., 1.),
+                rng.gen_range(-1., 1.),
+            )
+            .unit_vector()
+        })
+        .collect()
+}
+
+fn perlin_generate_perm<R>(rng: &mut R) -> Vec<usize>
+where
+    R: Rng,
+{
+    let mut p: Vec<usize> = (0..256).map(|i| i).collect();
+    rng.shuffle(&mut p);
+    p
+}
+
+fn perlin_interp(c: [[[Vec3; 2]; 2]; 2], u: f32, v: f32, w: f32) -> f32 {
+    // Hermite cubic to round off interpolation and attempt to address 'mach bands'.
+    let uu = u * u * (3. - 2. * u);
+    let vv = v * v * (3. - 2. * v);
+    let ww = w * w * (3. - 2. * w);
+
+    let mut accum = 0.;
+    for i in 0..2 {
+        for j in 0..2 {
+            for k in 0..2 {
+                let weight_v = Vec3::new(u - i as f32, v - j as f32, w - k as f32);
+
+                let i = i as f32;
+                let j = j as f32;
+                let k = k as f32;
+                accum += (i * uu + (1. - i) * (1. - uu))
+                    * (j * vv + (1. - j) * (1. - vv))
+                    * (k * ww + (1. - k) * (1. - ww))
+                    * dot(c[i as usize][j as usize][k as usize], weight_v);
+            }
+        }
+    }
+    //info!("u {} v {} accum {}", u, v, accum);
+    accum
+}
+
+impl Perlin {
+    pub fn new<R>(rng: &mut R) -> Perlin
+    where
+        R: Rng,
+    {
+        let p = Perlin {
+            ran_vec: perlin_generate(rng),
+            perm_x: perlin_generate_perm(rng),
+            perm_y: perlin_generate_perm(rng),
+            perm_z: perlin_generate_perm(rng),
+        };
+        trace!(target: "perlin",
+            "ran_vec: {}",
+            p.ran_vec
+                .iter()
+                .map(|v| v.to_string())
+                .collect::<Vec<String>>()
+                .join(", ")
+        );
+        trace!(target: "perlin",
+            "perm_x: {}",
+            p.perm_x
+                .iter()
+                .map(|v| v.to_string())
+                .collect::<Vec<String>>()
+                .join(", ")
+        );
+        trace!(target: "perlin",
+            "perm_y: {}",
+            p.perm_y
+                .iter()
+                .map(|v| v.to_string())
+                .collect::<Vec<String>>()
+                .join(", ")
+        );
+        trace!(target: "perlin",
+            "perm_z: {}",
+            p.perm_z
+                .iter()
+                .map(|v| v.to_string())
+                .collect::<Vec<String>>()
+                .join(", ")
+        );
+        p
+    }
+
+    pub fn turb(&self, p: Vec3, depth: usize) -> f32 {
+        let mut accum = 0.;
+        let mut temp_p = p;
+        let mut weight = 1.;
+        for _ in 0..depth {
+            accum += weight * self.value(temp_p);
+            weight *= 0.5;
+            temp_p = temp_p * 0.2;
+        }
+        accum.abs()
+    }
+}
+
+impl NoiseSource for Perlin {
+    fn value(&self, p: Vec3) -> f32 {
+        let u = p.x - p.x.floor();
+        let v = p.y - p.y.floor();
+        let w = p.z - p.z.floor();
+
+        let i = p.x.floor() as usize;
+        let j = p.y.floor() as usize;
+        let k = p.z.floor() as usize;
+
+        let mut c: [[[Vec3; 2]; 2]; 2] = Default::default();
+
+        // Squelch warning about di only being used to index, as this way reads more consistently.
+        #[allow(clippy::needless_range_loop)]
+        for di in 0..2 {
+            for dj in 0..2 {
+                for dk in 0..2 {
+                    c[di][dj][dk] = self.ran_vec[self.perm_x[(i + di) & 255]
+                        ^ self.perm_y[(j + dj) & 255]
+                        ^ self.perm_z[(k + dk) & 255]]
+                }
+            }
+        }
+        (1. + perlin_interp(c, u, v, w)) * 0.5
+    }
+}

rtiow/renderer/src/output.rs

@@ -0,0 +1,222 @@
+use std::collections::HashMap;
+use std::fs::File;
+use std::io::BufWriter;
+use std::path::Path;
+use std::sync::Arc;
+use std::sync::Mutex;
+use std::time;
+
+use chrono::Local;
+use image;
+use lazy_static::lazy_static;
+use log::info;
+use serde_derive::Serialize;
+
+use crate::renderer::Scene;
+use crate::vec3::Vec3;
+
+// Main RGB image output from rendering the scene.
+pub const MAIN_IMAGE: &str = "@final";
+// Debug image for adaptive pixels subsampling.
+// Red indicates recursion hit maximum depth splitting the pixel.
+// Green indicates no subdivision necessary
+pub const ADAPTIVE_DEPTH: &str = "adaptive_depth";
+// Grey scale showing rays cast per pixel.
+pub const RAYS_PER_PIXEL: &str = "rays_per_pixel";
+
+lazy_static! {
+    static ref DEBUGGER: Arc<Mutex<Debugger>> = Arc::new(Mutex::new(Debugger::new()));
+}
+
+#[derive(Serialize)]
+struct ImageMetadata {
+    name: String,
+    image: String,
+    binary: String,
+    ratio: f32,
+    size: (usize, usize),
+    format: ImageType,
+}
+#[derive(Serialize)]
+#[serde(rename_all = "camelCase")]
+struct Data<'s> {
+    timestamp: i64,
+    render_time_seconds: f32,
+    scene: &'s Scene,
+    image_metadata: Vec<ImageMetadata>,
+}
+
+#[derive(Clone, Copy, Serialize)]
+pub enum ImageType {
+    RGB01,
+    Grey01,
+    GreyNormalized,
+}
+
+struct Image {
+    w: usize,
+    h: usize,
+    pix: Vec<Vec3>,
+}
+
+impl Image {
+    fn new(w: usize, h: usize) -> Image {
+        Image {
+            w,
+            h,
+            pix: (0..w * h).map(|_| [0., 0., 0.].into()).collect(),
+        }
+    }
+
+    fn put_pixel(&mut self, x: usize, y: usize, p: Vec3) {
+        let offset = x + y * self.w;
+        self.pix[offset] = p;
+    }
+}
+
+struct Debugger {
+    images: HashMap<String, (ImageType, Image)>,
+}
+
+impl Debugger {
+    fn new() -> Debugger {
+        Debugger {
+            images: HashMap::new(),
+        }
+    }
+}
+
+pub fn register_image(name: String, dimensions: (usize, usize), it: ImageType) {
+    let mut debugger = DEBUGGER.lock().unwrap();
+    debugger
+        .images
+        .insert(name, (it, Image::new(dimensions.0, dimensions.1)));
+}
+
+pub fn set_pixel(name: &str, x: usize, y: usize, pixel: Vec3) {
+    let mut debugger = DEBUGGER.lock().unwrap();
+    let (_it, img) = debugger
+        .images
+        .get_mut(name)
+        .expect(&format!("couldn't find image named '{}'", name));
+    let y_inv = img.h - y - 1;
+    img.put_pixel(x, y_inv, pixel);
+}
+
+pub fn set_pixel_grey(name: &str, x: usize, y: usize, grey: f32) {
+    let mut debugger = DEBUGGER.lock().unwrap();
+    let (_it, img) = debugger
+        .images
+        .get_mut(name)
+        .expect(&format!("couldn't find image named '{}'", name));
+    let y_inv = img.h - y - 1;
+    img.put_pixel(x, y_inv, [grey, grey, grey].into());
+}
+
+trait ImageSaver {
+    fn save<Q>(&self, path: Q) -> std::io::Result<()>
+    where
+        Q: AsRef<Path> + Sized;
+}
+
+pub fn write_images<P: AsRef<Path>>(
+    scene: &Scene,
+    render_time: time::Duration,
+    output_dir: P,
+) -> std::io::Result<()> {
+    let output_dir: &Path = output_dir.as_ref();
+    let debugger = DEBUGGER.lock().unwrap();
+    let now = Local::now();
+    // Write out images in consistent order.
+    let mut names = debugger.images.keys().collect::<Vec<_>>();
+    names.sort();
+    let mut image_metadata = Vec::new();
+    for name in &names {
+        let (it, img) = debugger.images.get(*name).unwrap();
+        let image = format!("{}.png", name);
+        let binary = format!("{}.json", name);
+        let ratio = img.w as f32 / img.h as f32;
+        let size = (img.w, img.h);
+        let image_path = output_dir.join(&image);
+        let binary_path = output_dir.join(&binary);
+        image_metadata.push(ImageMetadata {
+            name: name.to_string(),
+            image,
+            binary,
+            ratio,
+            size,
+            format: *it,
+        });
+        info!("Saving {}", image_path.to_string_lossy());
+        match it {
+            ImageType::RGB01 => {
+                let mut out_img = image::RgbImage::new(img.w as u32, img.h as u32);
+                out_img
+                    .enumerate_pixels_mut()
+                    .enumerate()
+                    .for_each(|(i, (_x, _y, p))| {
+                        let pixel = img.pix[i];
+                        *p = image::Rgb([
+                            (pixel[0] * 255.).min(255.) as u8,
+                            (pixel[1] * 255.).min(255.) as u8,
+                            (pixel[2] * 255.).min(255.) as u8,
+                        ])
+                    });
+                out_img.save(image_path)?;
+            }
+            ImageType::Grey01 => {
+                let mut out_img = image::GrayImage::new(img.w as u32, img.h as u32);
+                out_img
+                    .enumerate_pixels_mut()
+                    .enumerate()
+                    .for_each(|(i, (_x, _y, p))| {
+                        let pixel = img.pix[i];
+                        *p = image::Luma([(pixel[0] * 255.).min(255.) as u8])
+                    });
+                out_img.save(image_path)?;
+            }
+            ImageType::GreyNormalized => {
+                let mut out_img = image::GrayImage::new(img.w as u32, img.h as u32);
+
+                let max_val = img.pix.iter().map(|v| v.x).fold(0., f32::max);
+                out_img
+                    .enumerate_pixels_mut()
+                    .enumerate()
+                    .for_each(|(i, (_x, _y, p))| {
+                        let pixel = img.pix[i];
+                        *p = image::Luma([(pixel[0] / max_val * 255.).min(255.) as u8])
+                    });
+                out_img.save(image_path)?;
+            }
+        };
+        info!("Saving {}", binary_path.to_string_lossy());
+        let f = File::create(output_dir.join(binary_path))?;
+        let f = BufWriter::new(f);
+        match it {
+            ImageType::RGB01 => {
+                serde_json::ser::to_writer(
+                    f,
+                    &img.pix
+                        .iter()
+                        .map(|v| [v.x, v.y, v.z])
+                        .collect::<Vec<[f32; 3]>>(),
+                )?;
+            }
+            ImageType::Grey01 | ImageType::GreyNormalized => {
+                serde_json::ser::to_writer(f, &img.pix.iter().map(|v| v.x).collect::<Vec<f32>>())?;
+            }
+        };
+    }
+    let f = File::create(output_dir.join("data.json"))?;
+    let f = BufWriter::new(f);
+    serde_json::ser::to_writer(
+        f,
+        &Data {
+            timestamp: now.timestamp(),
+            render_time_seconds: render_time.as_secs_f32(),
+            scene,
+            image_metadata,
+        },
+    )?;
+    Ok(())
+}

rtiow/renderer/src/ray.rs

@@ -0,0 +1,35 @@
+use crate::vec3::Vec3;
+
+#[derive(Copy, Clone, Debug, Default)]
+pub struct Ray {
+    pub origin: Vec3,
+    pub direction: Vec3,
+    pub time: f32,
+    pub inv_direction: Vec3,
+    pub sign: [usize; 3],
+}
+
+impl Ray {
+    pub fn new<V>(origin: V, direction: V, time: f32) -> Ray
+    where
+        V: Into<Vec3>,
+    {
+        let direction = direction.into();
+        let origin = origin.into();
+        let inv = 1. / direction;
+        Ray {
+            origin,
+            direction,
+            time,
+            inv_direction: inv,
+            sign: [
+                (inv.x < 0.) as usize,
+                (inv.y < 0.) as usize,
+                (inv.z < 0.) as usize,
+            ],
+        }
+    }
+    pub fn point_at_parameter(self, t: f32) -> Vec3 {
+        self.origin + self.direction * t
+    }
+}

rtiow/renderer/src/rect.rs

@@ -0,0 +1,191 @@
+// There are many math functions in this file, so we allow single letter variable names.
+#![allow(clippy::many_single_char_names)]
+use crate::aabb::AABB;
+use crate::hitable::Hit;
+use crate::hitable::HitRecord;
+use crate::material::Material;
+use crate::ray::Ray;
+use crate::vec3::Vec3;
+
+pub struct XYRect<M>
+where
+    M: Material,
+{
+    x0: f32,
+    x1: f32,
+    y0: f32,
+    y1: f32,
+    k: f32,
+    material: M,
+}
+
+impl<M> XYRect<M>
+where
+    M: Material,
+{
+    pub fn new(x0: f32, x1: f32, y0: f32, y1: f32, k: f32, material: M) -> XYRect<M> {
+        XYRect {
+            x0,
+            x1,
+            y0,
+            y1,
+            k,
+            material,
+        }
+    }
+}
+
+impl<M> Hit for XYRect<M>
+where
+    M: Material,
+{
+    fn hit(&self, r: Ray, t_min: f32, t_max: f32) -> Option<HitRecord> {
+        let t = (self.k - r.origin.z) / r.direction.z;
+        if t < t_min || t > t_max {
+            return None;
+        }
+        let x = r.origin.x + t * r.direction.x;
+        let y = r.origin.y + t * r.direction.y;
+        if x < self.x0 || x > self.x1 || y < self.y0 || y > self.y1 {
+            return None;
+        }
+        let u = (x - self.x0) / (self.x1 - self.x0);
+        let v = (y - self.y0) / (self.y1 - self.y0);
+        Some(HitRecord {
+            t,
+            uv: (u, v),
+            p: r.point_at_parameter(t),
+            normal: Vec3::new(0., 0., 1.),
+            material: &self.material,
+        })
+    }
+
+    fn bounding_box(&self, _t_min: f32, _t_max: f32) -> Option<AABB> {
+        Some(AABB::new(
+            Vec3::new(self.x0, self.y0, self.k - 0.0001),
+            Vec3::new(self.x1, self.y1, self.k + 0.0001),
+        ))
+    }
+}
+
+pub struct XZRect<M>
+where
+    M: Material,
+{
+    x0: f32,
+    x1: f32,
+    z0: f32,
+    z1: f32,
+    k: f32,
+    material: M,
+}
+
+impl<M> XZRect<M>
+where
+    M: Material,
+{
+    pub fn new(x0: f32, x1: f32, z0: f32, z1: f32, k: f32, material: M) -> XZRect<M> {
+        XZRect {
+            x0,
+            x1,
+            z0,
+            z1,
+            k,
+            material,
+        }
+    }
+}
+
+impl<M> Hit for XZRect<M>
+where
+    M: Material,
+{
+    fn hit(&self, r: Ray, t_min: f32, t_max: f32) -> Option<HitRecord> {
+        let t = (self.k - r.origin.y) / r.direction.y;
+        if t < t_min || t > t_max {
+            return None;
+        }
+        let x = r.origin.x + t * r.direction.x;
+        let z = r.origin.z + t * r.direction.z;
+        if x < self.x0 || x > self.x1 || z < self.z0 || z > self.z1 {
+            return None;
+        }
+        let u = (x - self.x0) / (self.x1 - self.x0);
+        let v = (z - self.z0) / (self.z1 - self.z0);
+        Some(HitRecord {
+            t,
+            uv: (u, v),
+            p: r.point_at_parameter(t),
+            normal: Vec3::new(0., 1., 0.),
+            material: &self.material,
+        })
+    }
+
+    fn bounding_box(&self, _t_min: f32, _t_max: f32) -> Option<AABB> {
+        Some(AABB::new(
+            Vec3::new(self.x0, self.k - 0.0001, self.z0),
+            Vec3::new(self.x1, self.k + 0.0001, self.z1),
+        ))
+    }
+}
+
+pub struct YZRect<M>
+where
+    M: Material,
+{
+    y0: f32,
+    y1: f32,
+    k: f32,
+    z0: f32,
+    z1: f32,
+    material: M,
+}
+
+impl<M> YZRect<M>
+where
+    M: Material,
+{
+    pub fn new(y0: f32, y1: f32, z0: f32, z1: f32, k: f32, material: M) -> YZRect<M> {
+        YZRect {
+            y0,
+            y1,
+            z0,
+            z1,
+            k,
+            material,
+        }
+    }
+}
+
+impl<M> Hit for YZRect<M>
+where
+    M: Material,
+{
+    fn hit(&self, r: Ray, t_min: f32, t_max: f32) -> Option<HitRecord> {
+        let t = (self.k - r.origin.x) / r.direction.x;
+        if t < t_min || t > t_max {
+            return None;
+        }
+        let y = r.origin.y + t * r.direction.y;
+        let z = r.origin.z + t * r.direction.z;
+        if y < self.y0 || y > self.y1 || z < self.z0 || z > self.z1 {
+            return None;
+        }
+        let u = (y - self.y0) / (self.y1 - self.y0);
+        let v = (z - self.z0) / (self.z1 - self.z0);
+        Some(HitRecord {
+            t,
+            uv: (u, v),
+            p: r.point_at_parameter(t),
+            normal: Vec3::new(1., 0., 0.),
+            material: &self.material,
+        })
+    }
+
+    fn bounding_box(&self, _t_min: f32, _t_max: f32) -> Option<AABB> {
+        Some(AABB::new(
+            Vec3::new(self.k - 0.0001, self.y0, self.z0),
+            Vec3::new(self.k + 0.0001, self.y1, self.z1),
+        ))
+    }
+}

rtiow/renderer/src/renderer.rs

@@ -0,0 +1,649 @@
+use std::fmt;
+use std::ops::AddAssign;
+use std::ops::Range;
+use std::path::Path;
+use std::path::PathBuf;
+use std::str;
+use std::sync;
+use std::sync::mpsc::sync_channel;
+use std::sync::mpsc::Receiver;
+use std::sync::mpsc::SyncSender;
+use std::sync::Arc;
+use std::sync::Mutex;
+use std::thread;
+use std::time;
+
+use core_affinity;
+use log::info;
+use log::trace;
+use num_cpus;
+use rand;
+use rand::Rng;
+use serde_derive::Serialize;
+use structopt::StructOpt;
+
+use crate::camera::Camera;
+use crate::hitable::Hit;
+use crate::human;
+use crate::material::Lambertian;
+use crate::output;
+use crate::ray::Ray;
+use crate::scenes;
+use crate::sphere::Sphere;
+use crate::texture::ConstantTexture;
+use crate::texture::EnvMap;
+use crate::vec3::Vec3;
+
+#[derive(Debug)]
+pub enum Model {
+    BVH,
+    Bench,
+    Book,
+    CornellBox,
+    CornellSmoke,
+    Final,
+    Mandelbrot,
+    PerlinDebug,
+    Spheramid,
+    Test,
+    Tutorial,
+}
+
+impl Model {
+    pub fn scene(&self, opt: &Opt) -> Scene {
+        match self {
+            Model::BVH => scenes::bvh::new(&opt),
+            Model::Bench => scenes::bench::new(&opt),
+            Model::Book => scenes::book::new(&opt),
+            Model::CornellBox => scenes::cornell_box::new(&opt),
+            Model::CornellSmoke => scenes::cornell_smoke::new(&opt),
+            Model::Final => scenes::final_scene::new(&opt),
+            Model::Mandelbrot => scenes::mandelbrot::new(&opt),
+            Model::PerlinDebug => scenes::perlin_debug::new(&opt),
+            Model::Spheramid => scenes::spheramid::new(&opt),
+            Model::Test => scenes::test::new(&opt),
+            Model::Tutorial => scenes::tutorial::new(&opt),
+        }
+    }
+}
+
+#[derive(Debug)]
+pub struct ModelParseError(String);
+
+impl fmt::Display for ModelParseError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "unknown model enum type '{}'", self.0)
+    }
+}
+
+impl str::FromStr for Model {
+    type Err = ModelParseError;
+    fn from_str(s: &str) -> std::result::Result<Self, Self::Err> {
+        match s {
+            "bench" => Ok(Model::Bench),
+            "book" => Ok(Model::Book),
+            "bvh" => Ok(Model::BVH),
+            "cornell_box" => Ok(Model::CornellBox),
+            "cornell_smoke" => Ok(Model::CornellSmoke),
+            "final" => Ok(Model::Final),
+            "mandelbrot" => Ok(Model::Mandelbrot),
+            "perlin_debug" => Ok(Model::PerlinDebug),
+            "spheramid" => Ok(Model::Spheramid),
+            "test" => Ok(Model::Test),
+            "tutorial" => Ok(Model::Tutorial),
+            _ => Err(ModelParseError(s.to_owned())),
+        }
+    }
+}
+
+impl std::string::ToString for Model {
+    fn to_string(&self) -> String {
+        match self {
+            Model::BVH => "bvh".to_string(),
+            Model::Bench => "bench".to_string(),
+            Model::Book => "book".to_string(),
+            Model::CornellBox => "cornell_box".to_string(),
+            Model::CornellSmoke => "cornell_smoke".to_string(),
+            Model::Final => "final".to_string(),
+            Model::Mandelbrot => "mandelbrot".to_string(),
+            Model::PerlinDebug => "perlin_debug".to_string(),
+            Model::Spheramid => "spheramid".to_string(),
+            Model::Test => "test".to_string(),
+            Model::Tutorial => "tutorial".to_string(),
+        }
+    }
+}
+
+#[derive(Debug, StructOpt)]
+#[structopt(name = "tracer", about = "An experimental ray tracer.")]
+pub struct Opt {
+    /// Image width
+    #[structopt(short = "w", long = "width", default_value = "512")]
+    pub width: usize,
+    /// Image height
+    #[structopt(short = "h", long = "height", default_value = "512")]
+    pub height: usize,
+    /// Number of threads
+    #[structopt(short = "t", long = "num_threads")]
+    pub num_threads: Option<usize>,
+    /// Sub-samples per pixel
+    #[structopt(short = "s", long = "subsample", default_value = "8")]
+    pub subsamples: usize,
+    /// Select scene to render, one of: "bench", "book", "tutorial", "bvh", "test", "cornell_box",
+    /// "cornell_smoke", "perlin_debug", "final"
+    #[structopt(long = "model", default_value = "book")]
+    pub model: Model,
+    /// Path to store pprof profile data, i.e. /tmp/cpuprofile.pprof
+    #[structopt(long = "pprof", parse(from_os_str))]
+    pub pprof: Option<PathBuf>,
+    /// Use acceleration data structure, may be BVH or kd-tree depending on scene.
+    #[structopt(long = "use_accel")]
+    pub use_accel: bool,
+
+    /// Output directory
+    #[structopt(parse(from_os_str), default_value = "/tmp/tracer")]
+    pub output: PathBuf,
+}
+
+pub fn opt_hash(opt: &Opt) -> String {
+    // TODO(wathiede): add threads.
+    format!(
+        "w:{}-h:{}-s:{}-pprof:{}-model:{}-use_accel:{}-{}",
+        opt.width,
+        opt.height,
+        opt.subsamples,
+        opt.pprof.is_some(),
+        opt.model.to_string(),
+        opt.use_accel,
+        opt.output.display().to_string().replace("/", "_")
+    )
+}
+
+// TODO(wathiede): implement the skips and then the renderer could use json as an input file type.
+#[derive(Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct Scene {
+    #[serde(skip)]
+    pub world: Box<dyn Hit>,
+    #[serde(skip)]
+    pub camera: Camera,
+    pub subsamples: usize,
+    /// overrides subsamples setting.
+    pub adaptive_subsampling: Option<f32>,
+    pub num_threads: Option<usize>,
+    pub width: usize,
+    pub height: usize,
+    pub global_illumination: bool,
+    #[serde(skip)]
+    pub env_map: Option<EnvMap>,
+}
+
+impl Default for Scene {
+    fn default() -> Scene {
+        let lookfrom = Vec3::new(20., 20., 20.);
+        let lookat = Vec3::new(0., 0., 0.);
+        let dist_to_focus = (lookfrom - lookat).length();
+        let aperture = 0.1;
+        let time_min = 0.;
+        let time_max = 1.;
+        let camera = Camera::new(
+            lookfrom,
+            lookat,
+            Vec3::new(0., 1., 0.),
+            70.,
+            1.,
+            aperture,
+            dist_to_focus,
+            time_min,
+            time_max,
+        );
+        Scene {
+            world: Box::new(Sphere::new(
+                Vec3::new(0., 0., 0.),
+                1.0,
+                Lambertian::new(ConstantTexture::new([0., 1., 0.])),
+            )),
+            camera,
+            subsamples: 0,
+            adaptive_subsampling: None,
+            num_threads: None,
+            width: 0,
+            height: 0,
+            global_illumination: false,
+            env_map: None,
+        }
+    }
+}
+
+// color will trace ray up to 50 bounces deep accumulating color as it goes.  If
+// global_illumination is true, a default light background color is assumed and will light the
+// world.  If false, it is expected the scene has emissive light sources.
+fn color(
+    r: Ray,
+    world: &dyn Hit,
+    depth: usize,
+    global_illumination: bool,
+    env_map: &Option<EnvMap>,
+) -> (Vec3, usize) {
+    if let Some(rec) = world.hit(r, 0.001, std::f32::MAX) {
+        let (u, v) = rec.uv;
+        let emitted = rec.material.emitted(u, v, rec.p);
+        let scatter_response = rec.material.scatter(&r, &rec);
+        if depth < 50 && scatter_response.reflected {
+            let (c, rays) = color(
+                scatter_response.scattered,
+                world,
+                depth + 1,
+                global_illumination,
+                env_map,
+            );
+            return (emitted + scatter_response.attenutation * c, rays + 1);
+        } else {
+            return (emitted, 1);
+        }
+    }
+    if global_illumination {
+        return match env_map {
+            Some(env_map) => (env_map.color(r.direction.unit_vector()), 1),
+            None => {
+                let unit_direction = r.direction.unit_vector();
+                // No hit, choose color from background.
+                let t = 0.5 * (unit_direction.y + 1.);
+                (
+                    Vec3::new(1., 1., 1.) * (1. - t) + Vec3::new(0.5, 0.7, 1.) * t,
+                    1,
+                )
+            }
+        };
+    }
+    // No global illumination, so background is black.
+    (Vec3::new(0., 0., 0.), 1)
+}
+
+const MAX_ADAPTIVE_DEPTH: usize = 10;
+fn trace_pixel_adaptive(
+    depth: usize,
+    threshold: f32,
+    x: usize,
+    y: usize,
+    x_range: Range<f32>,
+    y_range: Range<f32>,
+    scene: &Scene,
+) -> (Vec3, usize) {
+    let w = scene.width as f32;
+    let h = scene.height as f32;
+    let x_mid = x_range.start + ((x_range.end - x_range.start) / 2.);
+    let y_mid = y_range.start + ((y_range.end - y_range.start) / 2.);
+    let mc = ((x_mid + x as f32) / w, (y_mid + y as f32) / h);
+    let (center, rays) = color(
+        scene.camera.get_ray(mc.0, mc.1),
+        scene.world.as_ref(),
+        0,
+        scene.global_illumination,
+        &scene.env_map,
+    );
+    if depth == 0 {
+        output::set_pixel(output::ADAPTIVE_DEPTH, x, y, [1., 0., 0.].into());
+        return (center, rays);
+    }
+    // t = top
+    // m = middle
+    // b = bottom
+    // l = left
+    // c = center
+    // r = right
+    let tl = (
+        (x_range.start + x as f32) / w,
+        (y_range.start + y as f32) / h,
+    );
+    let tr = ((x_range.end + x as f32) / w, (y_range.start + y as f32) / h);
+    let bl = ((x_range.start + x as f32) / w, (y_range.end + y as f32) / h);
+    let br = ((x_range.end + x as f32) / w, (y_range.end + y as f32) / h);
+
+    let (corners, rays) = [tl, tr, mc, bl, br]
+        .iter()
+        .map(|(u, v)| {
+            color(
+                scene.camera.get_ray(*u, *v),
+                scene.world.as_ref(),
+                0,
+                scene.global_illumination,
+                &scene.env_map,
+            )
+        })
+        .fold(
+            ([0., 0., 0.].into(), 0),
+            |(p1, r1): (Vec3, usize), (p2, r2): (Vec3, usize)| ((p1 + p2), (r1 + r2)),
+        );
+    let corners = corners / 5.;
+    if (corners - center).length() > threshold {
+        let tl = trace_pixel_adaptive(
+            depth - 1,
+            threshold,
+            x,
+            y,
+            x_range.start..x_mid,
+            y_range.start..y_mid,
+            scene,
+        );
+        let tr = trace_pixel_adaptive(
+            depth - 1,
+            threshold,
+            x,
+            y,
+            x_mid..x_range.end,
+            y_range.start..y_mid,
+            scene,
+        );
+        let bl = trace_pixel_adaptive(
+            depth - 1,
+            threshold,
+            x,
+            y,
+            x_range.start..x_mid,
+            y_mid..y_range.end,
+            scene,
+        );
+        let br = trace_pixel_adaptive(
+            depth - 1,
+            threshold,
+            x,
+            y,
+            x_mid..x_range.end,
+            y_mid..y_range.end,
+            scene,
+        );
+        let pixel = (tl.0 + tr.0 + bl.0 + br.0) / 4.;
+        let rays = tl.1 + tr.1 + bl.1 + br.1;
+        (pixel, rays)
+    } else {
+        if depth == MAX_ADAPTIVE_DEPTH {
+            output::set_pixel(output::ADAPTIVE_DEPTH, x, y, [0., 1., 0.].into());
+        }
+        (corners, rays)
+    }
+}
+
+fn trace_pixel_random(x: usize, y: usize, scene: &Scene) -> (Vec3, usize) {
+    let mut rng = rand::thread_rng();
+    let u = (rng.gen_range(0., 1.) + x as f32) / scene.width as f32;
+    let v = (rng.gen_range(0., 1.) + y as f32) / scene.height as f32;
+    let ray = scene.camera.get_ray(u, v);
+    color(
+        ray,
+        scene.world.as_ref(),
+        0,
+        scene.global_illumination,
+        &scene.env_map,
+    )
+}
+
+#[derive(Clone, Copy)]
+struct RenderStats {
+    rays: usize,
+    pixels: usize,
+}
+
+impl AddAssign for RenderStats {
+    fn add_assign(&mut self, other: Self) {
+        *self = Self {
+            rays: self.rays + other.rays,
+            pixels: self.pixels + other.pixels,
+        }
+    }
+}
+
+fn progress(
+    last_stat: &RenderStats,
+    current_stat: &RenderStats,
+    time_diff: time::Duration,
+    pixel_total: usize,
+) -> String {
+    let human = human::Formatter::new();
+    let pixel_diff = current_stat.pixels - last_stat.pixels;
+    let ray_diff = current_stat.rays - last_stat.rays;
+    format!(
+        "{:7} / {:7}pixels ({:2}%) {:7}pixels/s {:7}rays/s",
+        human.format(current_stat.pixels as f64),
+        human.format(pixel_total as f64),
+        100 * current_stat.pixels / pixel_total,
+        human.format(pixel_diff as f64 / time_diff.as_secs_f64()),
+        human.format(ray_diff as f64 / time_diff.as_secs_f64())
+    )
+}
+
+impl Default for RenderStats {
+    fn default() -> Self {
+        RenderStats { rays: 0, pixels: 0 }
+    }
+}
+
+enum Request {
+    Pixel { x: usize, y: usize },
+    Line { width: usize, y: usize },
+}
+
+enum Response {
+    Pixel {
+        x: usize,
+        y: usize,
+        pixel: Vec3,
+        rs: RenderStats,
+    },
+    Line {
+        y: usize,
+        pixels: Vec<Vec3>,
+        rs: RenderStats,
+    },
+}
+
+fn render_pixel(scene: &Scene, x: usize, y: usize) -> (Vec3, usize) {
+    let (pixel, rays) = if let Some(threshold) = scene.adaptive_subsampling {
+        trace_pixel_adaptive(
+            MAX_ADAPTIVE_DEPTH,
+            threshold,
+            x,
+            y,
+            0.0..1.0,
+            0.0..1.0,
+            scene,
+        )
+    } else {
+        let (pixel, rays) = (0..scene.subsamples)
+            .map(|_| trace_pixel_random(x, y, scene))
+            .fold(
+                ([0., 0., 0.].into(), 0),
+                |(p1, r1): (Vec3, usize), (p2, r2): (Vec3, usize)| ((p1 + p2), (r1 + r2)),
+            );
+        output::set_pixel_grey(output::RAYS_PER_PIXEL, x, y, rays as f32);
+        (pixel / scene.subsamples as f32, rays)
+    };
+    // Gamma correct, use gamma 2 correction, which is 1/gamma where gamma=2 which is 1/2 or
+    // sqrt.
+    (
+        Vec3::new(pixel[0].sqrt(), pixel[1].sqrt(), pixel[2].sqrt()),
+        rays,
+    )
+}
+
+fn render_worker(
+    tid: usize,
+    scene: &Scene,
+    input_chan: Arc<Mutex<Receiver<Request>>>,
+    output_chan: &SyncSender<Response>,
+) {
+    loop {
+        let job = { input_chan.lock().unwrap().recv() };
+        match job {
+            Err(err) => {
+                trace!("Shutting down render_worker {}: {}", tid, err);
+                return;
+            }
+            Ok(req) => match req {
+                Request::Line { width, y } => {
+                    trace!("tid {} width {} y {}", tid, width, y);
+                    let batch = false;
+                    if batch {
+                        let (pixels, rays): (Vec<Vec3>, Vec<usize>) = (0..width)
+                            .map(|x| render_pixel(scene, x, y))
+                            .collect::<Vec<(_, _)>>()
+                            .into_iter()
+                            .unzip();
+                        let rays = rays.iter().sum();
+                        output_chan
+                            .send(Response::Line {
+                                y,
+                                pixels,
+                                rs: RenderStats {
+                                    rays,
+                                    pixels: width,
+                                },
+                            })
+                            .expect("failed to send pixel response");
+                    } else {
+                        (0..width).for_each(|x| {
+                            let (pixel, rays) = render_pixel(scene, x, y);
+                            output_chan
+                                .send(Response::Pixel {
+                                    x,
+                                    y,
+                                    pixel,
+                                    rs: RenderStats { rays, pixels: 1 },
+                                })
+                                .expect("failed to send pixel response");
+                        });
+                    }
+                }
+                Request::Pixel { x, y } => {
+                    trace!("tid {} x {} y {}", tid, x, y);
+                    let (pixel, rays) = render_pixel(scene, x, y);
+                    output_chan
+                        .send(Response::Pixel {
+                            x,
+                            y,
+                            pixel,
+                            rs: RenderStats { rays, pixels: 1 },
+                        })
+                        .expect("failed to send line response");
+                }
+            },
+        }
+    }
+}
+
+pub fn render(scene: Scene, output_dir: &Path) -> std::result::Result<(), std::io::Error> {
+    let num_threads = scene.num_threads.unwrap_or_else(num_cpus::get);
+    let (pixel_req_tx, pixel_req_rx) = sync_channel(2 * num_threads);
+    let (pixel_resp_tx, pixel_resp_rx) = sync_channel(2 * num_threads);
+
+    let scene = Arc::new(scene);
+    let pixel_req_rx = Arc::new(Mutex::new(pixel_req_rx));
+    info!("Adaptive subsampling: {:?}", scene.adaptive_subsampling);
+    // Retrieve the IDs of all active CPU cores.
+    let core_ids = core_affinity::get_core_ids().unwrap();
+    let core_ids = if core_ids.len() > num_threads {
+        core_ids[..num_threads].to_vec()
+    } else {
+        core_ids
+    };
+    info!("Creating {} render threads", core_ids.len());
+    output::register_image(
+        output::MAIN_IMAGE.to_string(),
+        (scene.width, scene.height),
+        output::ImageType::RGB01,
+    );
+    if scene.adaptive_subsampling.is_some() {
+        output::register_image(
+            output::ADAPTIVE_DEPTH.to_string(),
+            (scene.width, scene.height),
+            output::ImageType::RGB01,
+        );
+    }
+    output::register_image(
+        output::RAYS_PER_PIXEL.to_string(),
+        (scene.width, scene.height),
+        output::ImageType::GreyNormalized,
+    );
+    // Create a thread for each active CPU core.
+    let mut handles = core_ids
+        .into_iter()
+        .enumerate()
+        .filter(|(i, _id)| *i < num_threads)
+        .map(|(i, id)| {
+            let s = sync::Arc::clone(&scene);
+            let pixel_req_rx = pixel_req_rx.clone();
+            let pixel_resp_tx = pixel_resp_tx.clone();
+            thread::spawn(move || {
+                core_affinity::set_for_current(id);
+                render_worker(i, &s, pixel_req_rx, &pixel_resp_tx);
+            })
+        })
+        .collect::<Vec<_>>();
+    drop(pixel_req_rx);
+    drop(pixel_resp_tx);
+
+    let start_time = time::Instant::now();
+    let (w, h) = (scene.width, scene.height);
+    handles.push(thread::spawn(move || {
+        let batch_line_requests = true;
+        if batch_line_requests {
+            for y in 0..h {
+                pixel_req_tx
+                    .send(Request::Line { width: w, y })
+                    .expect("failed to send line request");
+            }
+        } else {
+            for y in 0..h {
+                for x in 0..w {
+                    pixel_req_tx
+                        .send(Request::Pixel { x, y })
+                        .expect("failed to send pixel request");
+                }
+            }
+        }
+        drop(pixel_req_tx);
+    }));
+
+    info!("Rendering with {} subsamples", scene.subsamples);
+
+    let pixel_total = scene.width * scene.height;
+    let mut last_time = time::Instant::now();
+    let mut last_stat: RenderStats = Default::default();
+    let mut current_stat: RenderStats = Default::default();
+    for resp in pixel_resp_rx {
+        match resp {
+            Response::Pixel { x, y, pixel, rs } => {
+                current_stat += rs;
+                output::set_pixel(output::MAIN_IMAGE, x, y, pixel);
+            }
+            Response::Line { y, pixels, rs } => {
+                current_stat += rs;
+                for (x, pixel) in pixels.iter().enumerate() {
+                    output::set_pixel(output::MAIN_IMAGE, x, y, *pixel);
+                }
+            }
+        }
+
+        let now = time::Instant::now();
+        let time_diff = now - last_time;
+        if time_diff > time::Duration::from_secs(1) {
+            info!(
+                "{}",
+                progress(&last_stat, &current_stat, time_diff, pixel_total)
+            );
+            last_stat = current_stat;
+            last_time = now;
+        }
+    }
+    for thr in handles {
+        thr.join().expect("thread join");
+    }
+    let time_diff = time::Instant::now() - start_time;
+    info!(
+        "Runtime {} seconds {}",
+        time_diff.as_secs_f32(),
+        progress(&Default::default(), &current_stat, time_diff, pixel_total)
+    );
+
+    output::write_images(&scene, time_diff, output_dir)
+}

rtiow/renderer/src/rotate.rs

@@ -0,0 +1,99 @@
+use std::f32::consts::PI;
+use std::f32::MAX;
+use std::f32::MIN;
+
+use crate::aabb::AABB;
+use crate::hitable::Hit;
+use crate::hitable::HitRecord;
+use crate::ray::Ray;
+use crate::vec3::Vec3;
+
+pub struct RotateY<H>
+where
+    H: Hit,
+{
+    hitable: H,
+    sin_theta: f32,
+    cos_theta: f32,
+    bbox: Option<AABB>,
+}
+
+impl<H> RotateY<H>
+where
+    H: Hit,
+{
+    pub fn new(hitable: H, angle: f32) -> RotateY<H> {
+        let radians = PI / 180. * angle;
+        let sin_theta = radians.sin();
+        let cos_theta = radians.cos();
+        let mut min = vec![MAX, MAX, MAX];
+        let mut max = vec![MIN, MIN, MIN];
+        let bbox = hitable.bounding_box(0., 1.).unwrap();
+        for i in 0..2 {
+            for j in 0..2 {
+                for k in 0..2 {
+                    let x = i as f32 * bbox.max().x + (1 - i) as f32 * bbox.min().x;
+                    let y = j as f32 * bbox.max().y + (1 - j) as f32 * bbox.min().y;
+                    let z = k as f32 * bbox.max().z + (1 - k) as f32 * bbox.min().z;
+                    let new_x = cos_theta * x + sin_theta * z;
+                    let new_z = -sin_theta * x + cos_theta * z;
+                    let tester = Vec3::new(new_x, y, new_z);
+                    for c in 0..3 {
+                        if tester[c] > max[c] {
+                            max[c] = tester[c];
+                        }
+                        if tester[c] < min[c] {
+                            min[c] = tester[c];
+                        }
+                    }
+                }
+            }
+        }
+        RotateY {
+            hitable,
+            sin_theta,
+            cos_theta,
+            bbox: Some(AABB::new(
+                Vec3::new(min[0], min[1], min[2]),
+                Vec3::new(max[0], max[1], max[2]),
+            )),
+        }
+    }
+}
+
+impl<H> Hit for RotateY<H>
+where
+    H: Hit,
+{
+    fn hit(&self, r: Ray, t_min: f32, t_max: f32) -> Option<HitRecord> {
+        let origin = Vec3::new(
+            self.cos_theta * r.origin[0] - self.sin_theta * r.origin[2],
+            r.origin.y,
+            self.sin_theta * r.origin[0] + self.cos_theta * r.origin[2],
+        );
+        let direction = Vec3::new(
+            self.cos_theta * r.direction[0] - self.sin_theta * r.direction[2],
+            r.direction.y,
+            self.sin_theta * r.direction[0] + self.cos_theta * r.direction[2],
+        );
+        let rotated_r = Ray::new(origin, direction, r.time);
+        if let Some(rec) = self.hitable.hit(rotated_r, t_min, t_max) {
+            let p = Vec3::new(
+                self.cos_theta * rec.p[0] + self.sin_theta * rec.p[2],
+                rec.p[1],
+                -self.sin_theta * rec.p[0] + self.cos_theta * rec.p[2],
+            );
+            let normal = Vec3::new(
+                self.cos_theta * rec.normal[0] + self.sin_theta * rec.normal[2],
+                rec.normal[1],
+                -self.sin_theta * rec.normal[0] + self.cos_theta * rec.normal[2],
+            );
+            return Some(HitRecord { p, normal, ..rec });
+        }
+        None
+    }
+
+    fn bounding_box(&self, _t_min: f32, _t_max: f32) -> Option<AABB> {
+        self.bbox.clone()
+    }
+}

rtiow/renderer/src/scenes/bench.rs

@@ -0,0 +1,78 @@
+use log::trace;
+use rand;
+use rand::Rng;
+
+use crate::bvh::BVH;
+use crate::camera::Camera;
+use crate::hitable::Hit;
+use crate::hitable_list::HitableList;
+use crate::kdtree::KDTree;
+use crate::material::Lambertian;
+use crate::renderer::Opt;
+use crate::renderer::Scene;
+use crate::sphere::Sphere;
+use crate::texture::ConstantTexture;
+use crate::vec3::Vec3;
+
+pub fn new(opt: &Opt) -> Scene {
+    let lookfrom = Vec3::new(20., 20., 20.);
+    let lookat = Vec3::new(0., 0., 0.);
+    let dist_to_focus = (lookfrom - lookat).length();
+    let aperture = 0.1;
+    let time_min = 0.;
+    let time_max = 1.;
+    let camera = Camera::new(
+        lookfrom,
+        lookat,
+        Vec3::new(0., 1., 0.),
+        70.,
+        opt.width as f32 / opt.height as f32,
+        aperture,
+        dist_to_focus,
+        time_min,
+        time_max,
+    );
+    let mut rng = rand::thread_rng();
+    let mut grid: Vec<Box<dyn Hit>> = Vec::new();
+    let len = 1000;
+    for x in 0..len {
+        for z in 0..len {
+            let r = rng.gen_range(0., 1.);
+            let g = rng.gen_range(0., 1.);
+            let b = rng.gen_range(0., 1.);
+
+            let x_pos = (x - len / 2) as f32 + rng.gen_range(-0.1, 0.1);
+            let z_pos = (z - len / 2) as f32 + rng.gen_range(-0.1, 0.1);
+
+            grid.push(Box::new(Sphere::new(
+                Vec3::new(x_pos, 0., z_pos),
+                0.5,
+                Lambertian::new(ConstantTexture::new(Vec3::new(r, g, b))),
+            )));
+        }
+    }
+    let world: Box<dyn Hit>;
+    if opt.use_accel {
+        let use_kd = true;
+        if use_kd {
+            let kdtree = KDTree::new(grid, time_min, time_max);
+            trace!("k-d tree world {}", kdtree);
+            world = Box::new(kdtree);
+        } else {
+            let bvh = BVH::new(grid, time_min, time_max);
+            trace!("BVH world {}", bvh);
+            world = Box::new(bvh);
+        }
+    } else {
+        world = Box::new(HitableList::new(grid));
+    }
+    Scene {
+        camera,
+        world,
+        subsamples: opt.subsamples,
+        num_threads: opt.num_threads,
+        width: opt.width,
+        height: opt.height,
+        ..Default::default()
+    }
+}

rtiow/renderer/src/scenes/book.rs

@@ -0,0 +1,144 @@
+use rand;
+use rand::Rng;
+
+use crate::camera::Camera;
+use crate::hitable::Hit;
+use crate::hitable_list::HitableList;
+use crate::kdtree::KDTree;
+use crate::material::Dielectric;
+use crate::material::Lambertian;
+use crate::material::Material;
+use crate::material::Metal;
+use crate::renderer::Opt;
+use crate::renderer::Scene;
+use crate::sphere::Sphere;
+use crate::texture::CheckerTexture;
+use crate::texture::ConstantTexture;
+use crate::texture::EnvMap;
+use crate::vec3::Vec3;
+
+pub fn new(opt: &Opt) -> Scene {
+    let lookfrom = Vec3::new(13., 2., 3.);
+    let lookat = Vec3::new(0., 0., 0.);
+    let dist_to_focus = 10.;
+    let aperture = 0.1;
+    let time_min = 0.;
+    let time_max = 1.;
+    let camera = Camera::new(
+        lookfrom,
+        lookat,
+        Vec3::new(0., 1., 0.),
+        20.,
+        opt.width as f32 / opt.height as f32,
+        aperture,
+        dist_to_focus,
+        time_min,
+        time_max,
+    );
+    let ground_color = if opt.use_accel {
+        [1.0, 0.4, 0.4]
+    } else {
+        [0.4, 1.0, 0.4]
+    };
+    let world: Box<dyn Hit> = if opt.use_accel {
+        Box::new(KDTree::new(random_scene(ground_color), time_min, time_max))
+    } else {
+        Box::new(HitableList::new(random_scene(ground_color)))
+    };
+    let skybox_bytes = include_bytes!("../../images/envmap.jpg");
+    let skybox = image::load_from_memory(skybox_bytes).unwrap().to_rgb();
+    Scene {
+        camera,
+        world,
+        subsamples: opt.subsamples,
+        adaptive_subsampling: Some(0.5),
+        num_threads: opt.num_threads,
+        width: opt.width,
+        height: opt.height,
+        global_illumination: true,
+        env_map: Some(EnvMap::new(skybox)),
+        ..Default::default()
+    }
+}
+
+fn random_scene<V>(ground_color: V) -> Vec<Box<dyn Hit>>
+where
+    V: Into<Vec3>,
+{
+    let mut rng = rand::thread_rng();
+    let checker = true;
+    let ground_material: Box<dyn Material> = if checker {
+        Box::new(Lambertian::new(CheckerTexture::new(
+            ConstantTexture::new([0., 0., 0.]),
+            ConstantTexture::new(ground_color),
+        )))
+    } else {
+        Box::new(Lambertian::new(ConstantTexture::new(ground_color)))
+    };
+
+    let mut objects: Vec<Box<dyn Hit>> = vec![Box::new(Sphere::new(
+        [0., -1000., 0.],
+        1000.,
+        ground_material,
+    ))];
+    let mut random = || rng.gen_range(0., 1.);
+
+    for a in -11..11 {
+        for b in -11..11 {
+            let choose_mat = random();
+            let center = Vec3::new(a as f32 + 0.9 * random(), 0.2, b as f32 + 0.9 * random());
+            if (center - Vec3::new(4., 0.2, 0.)).length() > 0.9 {
+                let sphere: Box<dyn Hit> = if choose_mat < 0.8 {
+                    // diffuse
+                    Box::new(Sphere::new(
+                        center,
+                        0.2,
+                        Lambertian::new(ConstantTexture::new([
+                            random() * random(),
+                            random() * random(),
+                            random() * random(),
+                        ])),
+                    ))
+                } else if choose_mat < 0.95 {
+                    // metal
+                    Box::new(Sphere::new(
+                        center,
+                        0.2,
+                        Metal::new(
+                            Vec3::new(
+                                0.5 * (1. + random()),
+                                0.5 * (1. + random()),
+                                0.5 * (1. + random()),
+                            ),
+                            0.5 * random(),
+                        ),
+                    ))
+                } else {
+                    // glass
+                    Box::new(Sphere::new(center, 0.2, Dielectric::new(1.5)))
+                };
+                objects.push(sphere);
+            };
+        }
+    }
+
+    let more: Vec<Box<dyn Hit>> = vec![
+        Box::new(Sphere::new(
+            Vec3::new(0., 1., 0.),
+            1.0,
+            Dielectric::new(1.5),
+        )),
+        Box::new(Sphere::new(
+            Vec3::new(-4., 1., 0.),
+            1.0,
+            Lambertian::new(ConstantTexture::new(Vec3::new(0.4, 0.2, 0.1))),
+        )),
+        Box::new(Sphere::new(
+            Vec3::new(4., 1., 0.),
+            1.0,
+            Metal::new(Vec3::new(0.7, 0.6, 0.5), 0.0),
+        )),
+    ];
+    objects.extend(more);
+    objects
+}

rtiow/renderer/src/scenes/bvh.rs

@@ -0,0 +1,73 @@
+use log::trace;
+
+use crate::bvh::BVH;
+use crate::camera::Camera;
+use crate::hitable::Hit;
+use crate::material::Lambertian;
+use crate::material::Metal;
+use crate::moving_sphere::MovingSphere;
+use crate::renderer::Opt;
+use crate::renderer::Scene;
+use crate::sphere::Sphere;
+use crate::texture::ConstantTexture;
+use crate::vec3::Vec3;
+
+pub fn new(opt: &Opt) -> Scene {
+    let lookfrom = Vec3::new(3., 3., 2.);
+    let lookat = Vec3::new(0., 0., -1.);
+    let dist_to_focus = (lookfrom - lookat).length();
+    let aperture = 0.1;
+    let time_min = 0.;
+    let time_max = 1.;
+    let camera = Camera::new(
+        lookfrom,
+        lookat,
+        Vec3::new(0., 1., 0.),
+        45.,
+        opt.width as f32 / opt.height as f32,
+        aperture,
+        dist_to_focus,
+        time_min,
+        time_max,
+    );
+    let b = BVH::new(
+        vec![
+            Box::new(Sphere::new(
+                Vec3::new(0., 0., -1.),
+                0.5,
+                Lambertian::new(ConstantTexture::new(Vec3::new(0.1, 0.2, 0.5))),
+            )),
+            Box::new(Sphere::new(
+                Vec3::new(0., -100.5, -1.),
+                100.,
+                Lambertian::new(ConstantTexture::new(Vec3::new(0.8, 0.8, 0.8))),
+            )),
+            Box::new(Sphere::new(
+                Vec3::new(1., 0., -1.),
+                0.5,
+                Metal::new(Vec3::new(0.6, 0.6, 0.6), 0.2),
+            )),
+            Box::new(MovingSphere::new(
+                Vec3::new(-1., 0., -1.25),
+                Vec3::new(-1., 0., -0.75),
+                0.5,
+                time_min,
+                time_max,
+                Lambertian::new(ConstantTexture::new(Vec3::new(0.2, 0.8, 0.2))),
+            )),
+        ],
+        time_min,
+        time_max,
+    );
+    trace!(target: "bvh", "World {}", b);
+    let world: Box<dyn Hit> = Box::new(b);
+    Scene {
+        camera,
+        world,
+        subsamples: opt.subsamples,
+        num_threads: opt.num_threads,
+        width: opt.width,
+        height: opt.height,
+        ..Default::default()
+    }
+}

rtiow/renderer/src/scenes/cornell_box.rs

@@ -0,0 +1,139 @@
+use std::sync::Arc;
+
+use crate::camera::Camera;
+use crate::cuboid::Cuboid;
+use crate::flip_normals::FlipNormals;
+use crate::hitable::Hit;
+use crate::hitable_list::HitableList;
+use crate::kdtree::KDTree;
+use crate::material::DiffuseLight;
+use crate::material::Lambertian;
+use crate::rect::XYRect;
+use crate::rect::XZRect;
+use crate::rect::YZRect;
+use crate::renderer::Opt;
+use crate::renderer::Scene;
+use crate::rotate::RotateY;
+use crate::texture::ConstantTexture;
+use crate::translate::Translate;
+use crate::vec3::Vec3;
+
+pub fn new(opt: &Opt) -> Scene {
+    let lookfrom = Vec3::new(278., 278., -800.);
+    let lookat = Vec3::new(278., 278., 0.);
+    let dist_to_focus = 10.0;
+    let aperture = 0.0;
+    let time_min = 0.;
+    let time_max = 1.;
+    let camera = Camera::new(
+        lookfrom,
+        lookat,
+        Vec3::new(0., 1., 0.),
+        40.,
+        opt.width as f32 / opt.height as f32,
+        aperture,
+        dist_to_focus,
+        time_min,
+        time_max,
+    );
+
+    let objects: Vec<Box<dyn Hit>> = vec![
+        // Box1
+        Box::new(Translate::new(
+            RotateY::new(
+                Cuboid::new(
+                    Vec3::new(0., 0., 0.),
+                    Vec3::new(165., 165., 165.),
+                    Arc::new(Lambertian::new(ConstantTexture::new(Vec3::new(
+                        0.73, 0.73, 0.73,
+                    )))),
+                ),
+                -18.,
+            ),
+            Vec3::new(100., 0., 0.),
+        )),
+        // Box2
+        Box::new(Translate::new(
+            RotateY::new(
+                Cuboid::new(
+                    Vec3::new(0., 0., 0.),
+                    Vec3::new(165., 330., 165.),
+                    Arc::new(Lambertian::new(ConstantTexture::new(Vec3::new(
+                        0.73, 0.73, 0.73,
+                    )))),
+                ),
+                15.,
+            ),
+            Vec3::new(265., 0., 295.),
+        )),
+        // Green wall left
+        Box::new(FlipNormals::new(YZRect::new(
+            0.,
+            555.,
+            0.,
+            555.,
+            555.,
+            Lambertian::new(ConstantTexture::new(Vec3::new(0.12, 0.45, 0.15))),
+        ))),
+        // Red floor right
+        Box::new(YZRect::new(
+            0.,
+            555.,
+            0.,
+            555.,
+            0.,
+            Lambertian::new(ConstantTexture::new(Vec3::new(0.65, 0.05, 0.05))),
+        )),
+        // Light in ceiling
+        Box::new(XZRect::new(
+            213.,
+            343.,
+            227.,
+            332.,
+            554.,
+            DiffuseLight::new(ConstantTexture::new(Vec3::new(15., 15., 15.))),
+        )),
+        // Grey ceiling
+        Box::new(FlipNormals::new(XZRect::new(
+            0.,
+            555.,
+            0.,
+            555.,
+            555.,
+            Lambertian::new(ConstantTexture::new(Vec3::new(0.73, 0.73, 0.73))),
+        ))),
+        // Grey floor
+        Box::new(XZRect::new(
+            0.,
+            555.,
+            0.,
+            555.,
+            0.,
+            Lambertian::new(ConstantTexture::new(Vec3::new(0.73, 0.73, 0.73))),
+        )),
+        // Grey back wall
+        Box::new(FlipNormals::new(XYRect::new(
+            0.,
+            555.,
+            0.,
+            555.,
+            555.,
+            Lambertian::new(ConstantTexture::new(Vec3::new(0.73, 0.73, 0.73))),
+        ))),
+    ];
+    let world: Box<dyn Hit> = if opt.use_accel {
+        Box::new(KDTree::new(objects, time_min, time_max))
+    } else {
+        Box::new(HitableList::new(objects))
+    };
+    Scene {
+        camera,
+        world,
+        subsamples: opt.subsamples,
+        num_threads: opt.num_threads,
+        width: opt.width,
+        height: opt.height,
+        global_illumination: false,
+        ..Default::default()
+    }
+}

rtiow/renderer/src/scenes/cornell_smoke.rs

@@ -0,0 +1,124 @@
+use std::sync::Arc;
+
+use crate::camera::Camera;
+use crate::constant_medium::ConstantMedium;
+use crate::cuboid::Cuboid;
+use crate::flip_normals::FlipNormals;
+use crate::hitable::Hit;
+use crate::hitable_list::HitableList;
+use crate::kdtree::KDTree;
+use crate::material::DiffuseLight;
+use crate::material::Lambertian;
+use crate::material::Material;
+use crate::rect::XYRect;
+use crate::rect::XZRect;
+use crate::rect::YZRect;
+use crate::renderer::Opt;
+use crate::renderer::Scene;
+use crate::rotate::RotateY;
+use crate::texture::ConstantTexture;
+use crate::translate::Translate;
+use crate::vec3::Vec3;
+
+pub fn new(opt: &Opt) -> Scene {
+    let lookfrom = Vec3::new(278., 278., -800.);
+    let lookat = Vec3::new(278., 278., 0.);
+    let dist_to_focus = 10.0;
+    let aperture = 0.0;
+    let time_min = 0.;
+    let time_max = 1.;
+    let camera = Camera::new(
+        lookfrom,
+        lookat,
+        Vec3::new(0., 1., 0.),
+        40.,
+        opt.width as f32 / opt.height as f32,
+        aperture,
+        dist_to_focus,
+        time_min,
+        time_max,
+    );
+
+    let red = Lambertian::new(ConstantTexture::new([0.65, 0.05, 0.05]));
+    let white: Arc<dyn Material> =
+        Arc::new(Lambertian::new(ConstantTexture::new([0.73, 0.73, 0.73])));
+    let green = Lambertian::new(ConstantTexture::new([0.12, 0.45, 0.15]));
+    let light = DiffuseLight::new(ConstantTexture::new([7., 7., 7.]));
+
+    let objects: Vec<Box<dyn Hit>> = vec![
+        // White smoke box on the right
+        Box::new(ConstantMedium::new(
+            Translate::new(
+                RotateY::new(
+                    Cuboid::new(
+                        Vec3::new(0., 0., 0.),
+                        Vec3::new(165., 165., 165.),
+                        Arc::clone(&white),
+                    ),
+                    -18.,
+                ),
+                Vec3::new(130., 0., 65.),
+            ),
+            0.01,
+            ConstantTexture::new([1., 1., 1.]),
+        )),
+        // Black smoke box on the left
+        Box::new(ConstantMedium::new(
+            Translate::new(
+                RotateY::new(
+                    Cuboid::new(
+                        Vec3::new(0., 0., 0.),
+                        Vec3::new(165., 330., 165.),
+                        Arc::clone(&white),
+                    ),
+                    15.,
+                ),
+                Vec3::new(265., 0., 295.),
+            ),
+            0.01,
+            ConstantTexture::new([0., 0., 0.]),
+        )),
+        // Green wall left
+        Box::new(FlipNormals::new(YZRect::new(
+            0., 555., 0., 555., 555., green,
+        ))),
+        // Red floor right
+        Box::new(YZRect::new(0., 555., 0., 555., 0., red)),
+        // Light in ceiling
+        Box::new(XZRect::new(113., 443., 127., 432., 554., light)),
+        // Grey ceiling
+        Box::new(FlipNormals::new(XZRect::new(
+            0.,
+            555.,
+            0.,
+            555.,
+            555.,
+            Arc::clone(&white),
+        ))),
+        // Grey floor
+        Box::new(XZRect::new(0., 555., 0., 555., 0., Arc::clone(&white))),
+        // Grey back wall
+        Box::new(FlipNormals::new(XYRect::new(
+            0.,
+            555.,
+            0.,
+            555.,
+            555.,
+            Arc::clone(&white),
+        ))),
+    ];
+    let world: Box<dyn Hit> = if opt.use_accel {
+        Box::new(KDTree::new(objects, time_min, time_max))
+    } else {
+        Box::new(HitableList::new(objects))
+    };
+    Scene {
+        camera,
+        world,
+        subsamples: opt.subsamples,
+        num_threads: opt.num_threads,
+        width: opt.width,
+        height: opt.height,
+        ..Default::default()
+    }
+}

rtiow/renderer/src/scenes/final_scene.rs

@@ -0,0 +1,177 @@
+use std::sync::Arc;
+
+use image;
+use rand;
+use rand::Rng;
+
+use crate::camera::Camera;
+use crate::constant_medium::ConstantMedium;
+use crate::cuboid::Cuboid;
+use crate::hitable::Hit;
+use crate::hitable_list::HitableList;
+use crate::kdtree::KDTree;
+use crate::material::Dielectric;
+use crate::material::DiffuseLight;
+use crate::material::Lambertian;
+use crate::material::Material;
+use crate::material::Metal;
+use crate::moving_sphere::MovingSphere;
+use crate::noise::perlin::Perlin;
+use crate::noise::NoiseType;
+use crate::rect::XZRect;
+use crate::renderer::Opt;
+use crate::renderer::Scene;
+use crate::rotate::RotateY;
+use crate::sphere::Sphere;
+use crate::texture::ConstantTexture;
+use crate::texture::ImageTexture;
+use crate::texture::NoiseTexture;
+use crate::translate::Translate;
+use crate::vec3::Vec3;
+
+pub fn new(opt: &Opt) -> Scene {
+    let lookfrom = Vec3::new(478., 278., -600.);
+    let lookat = Vec3::new(278., 278., 0.);
+    let dist_to_focus = 10.;
+    let aperture = 0.0;
+    let t_min = 0.;
+    let t_max = 1.;
+    let camera = Camera::new(
+        lookfrom,
+        lookat,
+        Vec3::new(0., 1., 0.),
+        40.,
+        opt.width as f32 / opt.height as f32,
+        aperture,
+        dist_to_focus,
+        t_min,
+        t_max,
+    );
+
+    let nb = 20;
+
+    let rng = &mut rand::thread_rng();
+    let mut boxlist: Vec<Box<dyn Hit>> = Vec::with_capacity(10000);
+    let mut list: Vec<Box<dyn Hit>> = Vec::new();
+    let white: Arc<dyn Material> =
+        Arc::new(Lambertian::new(ConstantTexture::new([0.73, 0.73, 0.73])));
+    let ground: Arc<dyn Material> =
+        Arc::new(Lambertian::new(ConstantTexture::new([0.48, 0.83, 0.53])));
+    for i in 0..nb {
+        for j in 0..nb {
+            let w = 100.;
+            let x0 = -1000. + i as f32 * w;
+            let z0 = -1000. + j as f32 * w;
+            let y0 = 0.;
+            let x1 = x0 + w;
+            let y1 = 100. * (rng.gen_range(0., 1.) + 0.01);
+            let z1 = z0 + w;
+            boxlist.push(Box::new(Cuboid::new(
+                Vec3::new(x0, y0, z0),
+                Vec3::new(x1, y1, z1),
+                Arc::clone(&ground),
+            )));
+        }
+    }
+    list.push(Box::new(KDTree::new(boxlist, t_min, t_max)));
+
+    let light = DiffuseLight::new(ConstantTexture::new([7., 7., 7.]));
+    // Light in ceiling
+    list.push(Box::new(XZRect::new(123., 423., 147., 412., 554., light)));
+
+    let center = Vec3::new(400., 400., 200.);
+    // Moving brownish ball
+    list.push(Box::new(MovingSphere::new(
+        center,
+        center + Vec3::new(30., 0., 0.),
+        50.,
+        t_min,
+        t_max,
+        Lambertian::new(ConstantTexture::new([0.7, 0.3, 0.1])),
+    )));
+
+    // Glass ball, lower-left corner
+    list.push(Box::new(Sphere::new(
+        [260., 150., 45.],
+        50.,
+        Dielectric::new(1.5),
+    )));
+    // Metal ball lower-right corner
+    list.push(Box::new(Sphere::new(
+        [0., 150., 145.],
+        50.,
+        Metal::new([0.8, 0.8, 0.9], 10.0),
+    )));
+
+    // Blue smokey glass ball lower-left
+    let boundary: Arc<dyn Hit> =
+        Arc::new(Sphere::new([360., 150., 145.], 70., Dielectric::new(1.5)));
+    list.push(Box::new(Arc::clone(&boundary)));
+    list.push(Box::new(ConstantMedium::new(
+        Arc::clone(&boundary),
+        0.2,
+        ConstantTexture::new([0.2, 0.4, 0.9]),
+    )));
+
+    // General white mist over whole scene
+    let boundary: Arc<dyn Hit> = Arc::new(Sphere::new([0., 0., 0.], 5000., Dielectric::new(1.5)));
+    list.push(Box::new(Arc::clone(&boundary)));
+    list.push(Box::new(ConstantMedium::new(
+        Arc::clone(&boundary),
+        0.0001,
+        ConstantTexture::new([1.0, 1.0, 1.0]),
+    )));
+
+    // Earth sphere
+    let world_image_bytes = include_bytes!("../../images/world.jpg");
+    let world = ImageTexture::new(image::load_from_memory(world_image_bytes).unwrap().to_rgb());
+    list.push(Box::new(Sphere::new(
+        Vec3::new(400., 200., 400.),
+        100.,
+        Lambertian::new(world),
+    )));
+
+    // Perlin noise sphere
+    let noise_source = Perlin::new(rng);
+    let noise_type = NoiseType::Marble {
+        period: Vec3::new(0., 1., 0.),
+        power: 4.,
+        size: 32,
+        scale: 0.5,
+    };
+    let pertext = NoiseTexture::new(noise_source, noise_type);
+    list.push(Box::new(Sphere::new(
+        [220., 280., 300.],
+        80.,
+        Lambertian::new(pertext),
+    )));
+
+    // White 'cube' made of 1000 spheres
+    let ns = 1000;
+    let mut boxlist: Vec<Box<dyn Hit>> = Vec::with_capacity(1000);
+    for _ in 0..ns {
+        boxlist.push(Box::new(Sphere::new(
+            [
+                165. * rng.gen_range(0., 1.),
+                165. * rng.gen_range(0., 1.),
+                165. * rng.gen_range(0., 1.),
+            ],
+            10.,
+            Arc::clone(&white),
+        )));
+    }
+    list.push(Box::new(Translate::new(
+        RotateY::new(KDTree::new(boxlist, t_min, t_max), 15.),
+        [-100., 270., 395.],
+    )));
+
+    Scene {
+        camera,
+        world: Box::new(HitableList::new(list)),
+        subsamples: opt.subsamples,
+        num_threads: opt.num_threads,
+        width: opt.width,
+        height: opt.height,
+        ..Default::default()
+    }
+}

rtiow/renderer/src/scenes/mandelbrot.rs

@@ -0,0 +1,157 @@
+use rand;
+
+use crate::camera::Camera;
+use crate::hitable::Hit;
+use crate::hitable_list::HitableList;
+use crate::kdtree::KDTree;
+use crate::material::DiffuseLight;
+use crate::material::Lambertian;
+use crate::noise::perlin::Perlin;
+use crate::noise::NoiseType;
+use crate::rect::XYRect;
+use crate::rect::XZRect;
+use crate::rect::YZRect;
+use crate::renderer::Opt;
+use crate::renderer::Scene;
+use crate::sphere::Sphere;
+use crate::texture::ConstantTexture;
+use crate::texture::ImageTexture;
+use crate::texture::Mandelbrot;
+use crate::texture::NoiseTexture;
+use crate::vec3::Vec3;
+
+pub fn new(opt: &Opt) -> Scene {
+    let lookfrom = Vec3::new(20., 20., 20.);
+    let lookat = Vec3::new(0., 1., 0.);
+    let dist_to_focus = 10.0;
+    let aperture = 0.0;
+    let time_min = 0.;
+    let time_max = 1.;
+    let camera = Camera::new(
+        lookfrom,
+        lookat,
+        Vec3::new(0., 1., 0.),
+        20.,
+        opt.width as f32 / opt.height as f32,
+        aperture,
+        dist_to_focus,
+        time_min,
+        time_max,
+    );
+    let rng = &mut rand::thread_rng();
+    let _ground_color = if opt.use_accel {
+        Box::new(ConstantTexture::new(Vec3::new(1.0, 0.4, 0.4)))
+    } else {
+        Box::new(ConstantTexture::new(Vec3::new(0.4, 1.0, 0.4)))
+    };
+
+    let world_image_bytes = include_bytes!("../../images/world.jpg");
+    let it = ImageTexture::new(image::load_from_memory(world_image_bytes).unwrap().to_rgb());
+    let noise_source = Perlin::new(rng);
+    let noise_type = NoiseType::Scale(10.);
+    let objects: Vec<Box<dyn Hit>> = vec![
+        // Textured globe
+        // Box::new(Sphere::new(Vec3::new(0., 2., 0.), 2.0, Lambertian::new(it))),
+        Box::new(Sphere::new(
+            Vec3::new(0., 2., 0.),
+            2.0,
+            DiffuseLight::new(it),
+        )),
+        // Ground
+        Box::new(XZRect::new(
+            -100.,
+            100.,
+            -100.,
+            1000.,
+            -60.,
+            DiffuseLight::new(Mandelbrot::default()),
+        )),
+        Box::new(XZRect::new(
+            -100.,
+            100.,
+            -100.,
+            200.,
+            60.,
+            DiffuseLight::new(ConstantTexture::new(Vec3::new(1., 1., 1.))),
+        )),
+        Box::new(YZRect::new(
+            1.,
+            3.,
+            -1.,
+            1.,
+            4.,
+            DiffuseLight::new(ConstantTexture::new(Vec3::new(4., 0., 4.))),
+        )),
+        Box::new(YZRect::new(
+            1.,
+            3.,
+            -1.,
+            1.,
+            -4.,
+            DiffuseLight::new(ConstantTexture::new(Vec3::new(0., 4., 0.))),
+        )),
+        Box::new(XZRect::new(
+            -1.,
+            1.,
+            -1.,
+            1.,
+            6.,
+            DiffuseLight::new(ConstantTexture::new(Vec3::new(4., 4., 0.))),
+        )),
+        Box::new(XYRect::new(
+            -1.,
+            1.,
+            1.,
+            3.,
+            -4.,
+            DiffuseLight::new(ConstantTexture::new(Vec3::new(0., 0., 4.))),
+        )),
+        Box::new(XYRect::new(
+            -1.75,
+            1.75,
+            1.,
+            3.,
+            4.,
+            Lambertian::new(NoiseTexture::new(noise_source, noise_type)),
+        )),
+        /*
+        Box::new(Sphere::new(
+            Vec3::new(0., 0., 0.),
+            0.5,
+            Box::new(Lambertian::new(ConstantTexture::new(Vec3::new(
+                0.1, 0.2, 0.5,
+            )))),
+        )),
+        // Shiny sphere
+        Box::new(Sphere::new(
+            Vec3::new(1., 0., 0.),
+            0.5,
+            Metal::new(Vec3::new(0.8, 0.8, 0.8), 0.2),
+        )),
+        Box::new(MovingSphere::new(
+            Vec3::new(-1., 0., -0.25),
+            Vec3::new(-1., 0., 0.25),
+            0.5,
+            0.,
+            1.,
+            Lambertian::new(ConstantTexture::new(Vec3::new(
+                0.2, 0.8, 0.2,
+            ))),
+        )),
+        */
+    ];
+    let world: Box<dyn Hit> = if opt.use_accel {
+        Box::new(KDTree::new(objects, time_min, time_max))
+    } else {
+        Box::new(HitableList::new(objects))
+    };
+    Scene {
+        camera,
+        world,
+        subsamples: opt.subsamples,
+        num_threads: opt.num_threads,
+        width: opt.width,
+        height: opt.height,
+        ..Default::default()
+    }
+}

rtiow/renderer/src/scenes/mod.rs

@@ -0,0 +1,11 @@
+pub mod bench;
+pub mod book;
+pub mod bvh;
+pub mod cornell_box;
+pub mod cornell_smoke;
+pub mod final_scene;
+pub mod mandelbrot;
+pub mod perlin_debug;
+pub mod spheramid;
+pub mod test;
+pub mod tutorial;

rtiow/renderer/src/scenes/perlin_debug.rs

@@ -0,0 +1,74 @@
+use std::sync::Arc;
+
+use rand;
+
+use crate::camera::Camera;
+use crate::hitable::Hit;
+use crate::hitable_list::HitableList;
+use crate::kdtree::KDTree;
+use crate::material::Lambertian;
+use crate::noise::perlin::Perlin;
+use crate::noise::NoiseType;
+use crate::renderer::Opt;
+use crate::renderer::Scene;
+use crate::sphere::Sphere;
+use crate::texture::NoiseTexture;
+use crate::texture::Texture;
+use crate::vec3::Vec3;
+
+pub fn new(opt: &Opt) -> Scene {
+    let lookfrom = Vec3::new(13., 2., 3.);
+    let lookat = Vec3::new(0., 0., 0.);
+    let dist_to_focus = 10.0;
+    let aperture = 0.0;
+    let time_min = 0.;
+    let time_max = 1.;
+    let camera = Camera::new(
+        lookfrom,
+        lookat,
+        Vec3::new(0., 1., 0.),
+        20.,
+        opt.width as f32 / opt.height as f32,
+        aperture,
+        dist_to_focus,
+        time_min,
+        time_max,
+    );
+    let rng = &mut rand::thread_rng();
+    let noise_source = Perlin::new(rng);
+    let noise_type = NoiseType::Marble {
+        period: Vec3::new(0., 1., 0.),
+        power: 4.,
+        size: 32,
+        scale: 0.05,
+    };
+    let pertext: Arc<dyn Texture> = Arc::new(NoiseTexture::new(noise_source, noise_type));
+
+    let objects: Vec<Box<dyn Hit>> = vec![
+        Box::new(Sphere::new(
+            Vec3::new(0., -1000., 0.),
+            1000.,
+            Lambertian::new(Arc::clone(&pertext)),
+        )),
+        Box::new(Sphere::new(
+            Vec3::new(0., 2., 0.),
+            2.0,
+            Lambertian::new(Arc::clone(&pertext)),
+        )),
+    ];
+    let world: Box<dyn Hit> = if opt.use_accel {
+        Box::new(KDTree::new(objects, time_min, time_max))
+    } else {
+        Box::new(HitableList::new(objects))
+    };
+    Scene {
+        camera,
+        world,
+        subsamples: opt.subsamples,
+        num_threads: opt.num_threads,
+        width: opt.width,
+        height: opt.height,
+        global_illumination: true,
+        ..Default::default()
+    }
+}

rtiow/renderer/src/scenes/spheramid.rs

@@ -0,0 +1,123 @@
+use crate::camera::Camera;
+use crate::hitable::Hit;
+use crate::hitable_list::HitableList;
+use crate::kdtree::KDTree;
+use crate::material::Dielectric;
+use crate::material::Lambertian;
+use crate::material::Metal;
+use crate::moving_sphere::MovingSphere;
+use crate::rect::XYRect;
+use crate::rect::XZRect;
+use crate::renderer::Opt;
+use crate::renderer::Scene;
+use crate::sphere::Sphere;
+use crate::texture::CheckerTexture;
+use crate::texture::ConstantTexture;
+use crate::texture::EnvMap;
+use crate::texture::Texture;
+use crate::vec3::Vec3;
+
+// Draws many spheres along each positive axis.
+// Blue X-positive
+// Green Y-positive
+// Red Z-positive
+fn draw_axises() -> Vec<Box<dyn Hit>> {
+    let half_diameter = 0.1;
+    let x = (0..100).map(|i| -> Box<dyn Hit> {
+        // X-axis
+        Box::new(Sphere::new(
+            Vec3::new(i as f32 * 2. * half_diameter, 0., 0.),
+            half_diameter,
+            Lambertian::new(ConstantTexture::new([0., 0., 1.])),
+        ))
+    });
+    let y = (0..100).map(|i| -> Box<dyn Hit> {
+        // Y-axis
+        Box::new(Sphere::new(
+            Vec3::new(0., i as f32 * 2. * half_diameter, 0.),
+            half_diameter,
+            Lambertian::new(ConstantTexture::new([0., 1., 0.])),
+        ))
+    });
+    let z = (0..100).map(|i| -> Box<dyn Hit> {
+        // Z-axis
+        Box::new(Sphere::new(
+            Vec3::new(0., 0., i as f32 * 2. * half_diameter),
+            half_diameter,
+            Lambertian::new(ConstantTexture::new([1., 0., 0.])),
+        ))
+    });
+    x.chain(y.chain(z)).collect()
+}
+
+pub fn new(opt: &Opt) -> Scene {
+    let lookfrom = Vec3::new(10., 10., 20.);
+    let lookat = Vec3::new(0., 0., 0.);
+    let dist_to_focus = (lookfrom - lookat).length();
+    let aperture = 0.1;
+    let time_min = 0.;
+    let time_max = 0.;
+    let camera = Camera::new(
+        lookfrom,
+        lookat,
+        Vec3::new(0., 0., 1.),
+        45.,
+        opt.width as f32 / opt.height as f32,
+        aperture,
+        dist_to_focus,
+        time_min,
+        time_max,
+    );
+    let ground_color = CheckerTexture::new(
+        ConstantTexture::new([0., 0., 0.]),
+        ConstantTexture::new([1.0, 1.0, 1.0]),
+    );
+
+    let mut objects: Vec<Box<dyn Hit>> = vec![
+        Box::new(XYRect::new(
+            -10.,
+            10.,
+            -10.,
+            10.,
+            0.,
+            Lambertian::new(ground_color),
+        )),
+        Box::new(Sphere::new([1., 0.5, 1.], 0.5, Dielectric::new(1.5))),
+        Box::new(Sphere::new(
+            Vec3::new(0., 0., 0.5),
+            0.5,
+            Lambertian::new(ConstantTexture::new(Vec3::new(0.1, 0.2, 0.5))),
+        )),
+        Box::new(Sphere::new(
+            Vec3::new(1., 0., -1.),
+            0.5,
+            Metal::new(Vec3::new(0.8, 0.6, 0.2), 0.2),
+        )),
+        Box::new(MovingSphere::new(
+            Vec3::new(-1., 0., -1.25),
+            Vec3::new(-1., 0., -0.75),
+            0.5,
+            0.,
+            1.,
+            Lambertian::new(ConstantTexture::new(Vec3::new(0.2, 0.8, 0.2))),
+        )),
+    ];
+    objects.extend(draw_axises());
+    //let world = Box::new(KDTree::new(objects, time_min, time_max));
+    let world = Box::new(HitableList::new(objects));
+    let skybox_bytes = include_bytes!("../../images/envmap.jpg");
+    let skybox = image::load_from_memory(skybox_bytes).unwrap().to_rgb();
+    Scene {
+        camera,
+        world,
+        subsamples: opt.subsamples,
+        adaptive_subsampling: None,
+        // adaptive_subsampling: Some(0.5),
+        num_threads: opt.num_threads,
+        width: opt.width,
+        height: opt.height,
+        global_illumination: true,
+        env_map: Some(EnvMap::new(skybox)),
+        ..Default::default()
+    }
+}

rtiow/renderer/src/scenes/test.rs

@@ -0,0 +1,150 @@
+use image;
+use rand;
+
+use crate::camera::Camera;
+use crate::hitable::Hit;
+use crate::hitable_list::HitableList;
+use crate::kdtree::KDTree;
+use crate::material::DiffuseLight;
+use crate::material::Lambertian;
+use crate::noise::perlin::Perlin;
+use crate::noise::NoiseType;
+use crate::rect::XYRect;
+use crate::rect::XZRect;
+use crate::rect::YZRect;
+use crate::renderer::Opt;
+use crate::renderer::Scene;
+use crate::sphere::Sphere;
+use crate::texture::ConstantTexture;
+use crate::texture::ImageTexture;
+use crate::texture::NoiseTexture;
+use crate::vec3::Vec3;
+
+pub fn new(opt: &Opt) -> Scene {
+    let lookfrom = Vec3::new(20., 20., 20.);
+    let lookat = Vec3::new(0., 1., 0.);
+    let dist_to_focus = 10.0;
+    let aperture = 0.0;
+    let time_min = 0.;
+    let time_max = 1.;
+    let camera = Camera::new(
+        lookfrom,
+        lookat,
+        Vec3::new(0., 1., 0.),
+        20.,
+        opt.width as f32 / opt.height as f32,
+        aperture,
+        dist_to_focus,
+        time_min,
+        time_max,
+    );
+    let rng = &mut rand::thread_rng();
+    let _ground_color = if opt.use_accel {
+        Box::new(ConstantTexture::new(Vec3::new(1.0, 0.4, 0.4)))
+    } else {
+        Box::new(ConstantTexture::new(Vec3::new(0.4, 1.0, 0.4)))
+    };
+
+    let world_image_bytes = include_bytes!("../../images/world.jpg");
+    let it = ImageTexture::new(image::load_from_memory(world_image_bytes).unwrap().to_rgb());
+    let noise_source = Perlin::new(rng);
+    let noise_type = NoiseType::Scale(10.);
+    let objects: Vec<Box<dyn Hit>> = vec![
+        // Big sphere
+        Box::new(Sphere::new(Vec3::new(0., 2., 0.), 2.0, Lambertian::new(it))),
+        // Earth sized sphere
+        Box::new(Sphere::new(
+            Vec3::new(0., -1000., 0.),
+            1000.,
+            // Box::new(Lambertian::new(ground_color)),
+            Lambertian::new(NoiseTexture::new(noise_source, noise_type)),
+        )),
+        Box::new(XZRect::new(
+            -100.,
+            100.,
+            -100.,
+            1000.,
+            60.,
+            DiffuseLight::new(ConstantTexture::new(Vec3::new(1., 1., 1.))),
+        )),
+        Box::new(YZRect::new(
+            1.,
+            3.,
+            -1.,
+            1.,
+            4.,
+            DiffuseLight::new(ConstantTexture::new(Vec3::new(4., 0., 4.))),
+        )),
+        Box::new(YZRect::new(
+            1.,
+            3.,
+            -1.,
+            1.,
+            -4.,
+            DiffuseLight::new(ConstantTexture::new(Vec3::new(0., 4., 0.))),
+        )),
+        Box::new(XZRect::new(
+            -1.,
+            1.,
+            -1.,
+            1.,
+            6.,
+            DiffuseLight::new(ConstantTexture::new(Vec3::new(4., 4., 0.))),
+        )),
+        Box::new(XYRect::new(
+            -1.,
+            1.,
+            1.,
+            3.,
+            -4.,
+            DiffuseLight::new(ConstantTexture::new(Vec3::new(0., 0., 4.))),
+        )),
+        Box::new(XYRect::new(
+            -1.,
+            1.,
+            1.,
+            3.,
+            4.,
+            DiffuseLight::new(ConstantTexture::new(Vec3::new(0., 4., 4.))),
+        )),
+        /*
+        Box::new(Sphere::new(
+            Vec3::new(0., 0., 0.),
+            0.5,
+            Box::new(Lambertian::new(ConstantTexture::new(Vec3::new(
+                0.1, 0.2, 0.5,
+            )))),
+        )),
+        // Shiny sphere
+        Box::new(Sphere::new(
+            Vec3::new(1., 0., 0.),
+            0.5,
+            Metal::new(Vec3::new(0.8, 0.8, 0.8), 0.2),
+        )),
+        Box::new(MovingSphere::new(
+            Vec3::new(-1., 0., -0.25),
+            Vec3::new(-1., 0., 0.25),
+            0.5,
+            0.,
+            1.,
+            Lambertian::new(ConstantTexture::new(Vec3::new(
+                0.2, 0.8, 0.2,
+            ))),
+        )),
+        */
+    ];
+    let world: Box<dyn Hit> = if opt.use_accel {
+        Box::new(KDTree::new(objects, time_min, time_max))
+    } else {
+        Box::new(HitableList::new(objects))
+    };
+    Scene {
+        camera,
+        world,
+        subsamples: opt.subsamples,
+        num_threads: opt.num_threads,
+        width: opt.width,
+        height: opt.height,
+        ..Default::default()
+    }
+}

rtiow/renderer/src/scenes/tutorial.rs

@@ -0,0 +1,88 @@
+use crate::camera::Camera;
+use crate::hitable::Hit;
+use crate::hitable_list::HitableList;
+use crate::kdtree::KDTree;
+use crate::material::Dielectric;
+use crate::material::Lambertian;
+use crate::material::Metal;
+use crate::moving_sphere::MovingSphere;
+use crate::renderer::Opt;
+use crate::renderer::Scene;
+use crate::sphere::Sphere;
+use crate::texture::CheckerTexture;
+use crate::texture::ConstantTexture;
+use crate::texture::Texture;
+use crate::vec3::Vec3;
+
+pub fn new(opt: &Opt) -> Scene {
+    let lookfrom = Vec3::new(3., 4., 2.);
+    let lookat = Vec3::new(0., 0., -1.);
+    let dist_to_focus = (lookfrom - lookat).length();
+    let aperture = 0.1;
+    let time_min = 0.;
+    let time_max = 0.;
+    let camera = Camera::new(
+        lookfrom,
+        lookat,
+        Vec3::new(0., 1., 0.),
+        45.,
+        opt.width as f32 / opt.height as f32,
+        aperture,
+        dist_to_focus,
+        time_min,
+        time_max,
+    );
+    let ground_color: Box<dyn Texture> = if opt.use_accel {
+        Box::new(CheckerTexture::new(
+            ConstantTexture::new([0., 0., 0.]),
+            ConstantTexture::new([1.0, 0.4, 0.4]),
+        ))
+    } else {
+        Box::new(ConstantTexture::new(Vec3::new(0.4, 1.0, 0.4)))
+    };
+
+    let objects: Vec<Box<dyn Hit>> = vec![
+        //let world: Box<Hit> = Box::new(HitableList::new(vec![
+        Box::new(Sphere::new([1., 0.5, 1.], 0.5, Dielectric::new(1.5))),
+        Box::new(Sphere::new(
+            Vec3::new(0., 0., -1.),
+            0.5,
+            Lambertian::new(ConstantTexture::new(Vec3::new(0.1, 0.2, 0.5))),
+        )),
+        Box::new(Sphere::new(
+            Vec3::new(0., -1000.5, -1.),
+            1000.,
+            Lambertian::new(ground_color),
+        )),
+        Box::new(Sphere::new(
+            Vec3::new(1., 0., -1.),
+            0.5,
+            Metal::new(Vec3::new(0.8, 0.6, 0.2), 0.2),
+        )),
+        Box::new(MovingSphere::new(
+            Vec3::new(-1., 0., -1.25),
+            Vec3::new(-1., 0., -0.75),
+            0.5,
+            0.,
+            1.,
+            Lambertian::new(ConstantTexture::new(Vec3::new(0.2, 0.8, 0.2))),
+        )),
+    ];
+    let world: Box<dyn Hit> = if opt.use_accel {
+        Box::new(KDTree::new(objects, time_min, time_max))
+    } else {
+        Box::new(HitableList::new(objects))
+    };
+    Scene {
+        camera,
+        world,
+        subsamples: opt.subsamples,
+        adaptive_subsampling: None,
+        // adaptive_subsampling: Some(0.5),
+        num_threads: opt.num_threads,
+        width: opt.width,
+        height: opt.height,
+        global_illumination: true,
+        ..Default::default()
+    }
+}

rtiow/renderer/src/sphere.rs

@@ -0,0 +1,89 @@
+use std::f32::consts::PI;
+
+use crate::aabb::AABB;
+use crate::hitable::Hit;
+use crate::hitable::HitRecord;
+use crate::material::Material;
+use crate::ray::Ray;
+use crate::vec3::dot;
+use crate::vec3::Vec3;
+
+pub struct Sphere<M>
+where
+    M: Material,
+{
+    center: Vec3,
+    radius: f32,
+    material: M,
+}
+
+pub fn get_sphere_uv(p: Vec3) -> (f32, f32) {
+    let phi = p.z.atan2(p.x);
+    let theta = p.y.asin();
+    let u = 1. - (phi + PI) / (2. * PI);
+    let v = (theta + PI / 2.) / PI;
+    (u, v)
+}
+
+impl<M> Sphere<M>
+where
+    M: Material,
+{
+    pub fn new<V>(center: V, radius: f32, material: M) -> Sphere<M>
+    where
+        V: Into<Vec3>,
+    {
+        Sphere {
+            center: center.into(),
+            radius,
+            material,
+        }
+    }
+}
+
+impl<M> Hit for Sphere<M>
+where
+    M: Material,
+{
+    fn hit(&self, r: Ray, t_min: f32, t_max: f32) -> Option<HitRecord> {
+        let oc = r.origin - self.center;
+        let a = dot(r.direction, r.direction);
+        let b = dot(oc, r.direction);
+        let c = dot(oc, oc) - self.radius * self.radius;
+        let discriminant = b * b - a * c;
+        if discriminant > 0. {
+            let temp = (-b - (b * b - a * c).sqrt()) / a;
+            if temp < t_max && temp > t_min {
+                let point = r.point_at_parameter(temp);
+                let uv = get_sphere_uv((point - self.center) / self.radius);
+                return Some(HitRecord {
+                    t: temp,
+                    uv,
+                    p: point,
+                    normal: (point - self.center) / self.radius,
+                    material: &self.material,
+                });
+            }
+            let temp = (-b + (b * b - a * c).sqrt()) / a;
+            if temp < t_max && temp > t_min {
+                let point = r.point_at_parameter(temp);
+                let uv = get_sphere_uv((point - self.center) / self.radius);
+                return Some(HitRecord {
+                    t: temp,
+                    uv,
+                    p: point,
+                    normal: (point - self.center) / self.radius,
+                    material: &self.material,
+                });
+            }
+        }
+        None
+    }
+
+    fn bounding_box(&self, _t_min: f32, _t_max: f32) -> Option<AABB> {
+        Some(AABB::new(
+            self.center - Vec3::new(self.radius, self.radius, self.radius),
+            self.center + Vec3::new(self.radius, self.radius, self.radius),
+        ))
+    }
+}

rtiow/renderer/src/texture/checker.rs

@@ -0,0 +1,33 @@
+use crate::texture::Texture;
+use crate::vec3::Vec3;
+
+pub struct CheckerTexture<T>
+where
+    T: Texture,
+{
+    odd: T,
+    even: T,
+}
+
+impl<T> CheckerTexture<T>
+where
+    T: Texture,
+{
+    pub fn new(odd: T, even: T) -> CheckerTexture<T> {
+        CheckerTexture { odd, even }
+    }
+}
+
+impl<T> Texture for CheckerTexture<T>
+where
+    T: Texture,
+{
+    fn value(&self, u: f32, v: f32, p: Vec3) -> Vec3 {
+        let sines = (10. * p.x).sin() * (10. * p.y).sin() * (10. * p.z).sin();
+        if sines < 0. {
+            self.odd.value(u, v, p)
+        } else {
+            self.even.value(u, v, p)
+        }
+    }
+}

rtiow/renderer/src/texture/constant.rs

@@ -0,0 +1,24 @@
+use crate::texture::Texture;
+use crate::vec3::Vec3;
+
+#[derive(Debug, PartialEq)]
+pub struct ConstantTexture {
+    color: Vec3,
+}
+
+impl ConstantTexture {
+    pub fn new<V>(color: V) -> ConstantTexture
+    where
+        V: Into<Vec3>,
+    {
+        ConstantTexture {
+            color: color.into(),
+        }
+    }
+}
+
+impl Texture for ConstantTexture {
+    fn value(&self, _u: f32, _v: f32, _p: Vec3) -> Vec3 {
+        self.color
+    }
+}

rtiow/renderer/src/texture/envmap.rs

@@ -0,0 +1,26 @@
+use std::f32;
+
+use image::RgbImage;
+
+use crate::texture::ImageTexture;
+use crate::texture::Texture;
+use crate::vec3::Vec3;
+
+#[derive(Debug)]
+pub struct EnvMap {
+    img_tex: ImageTexture,
+}
+
+impl EnvMap {
+    pub fn new(img: RgbImage) -> EnvMap {
+        EnvMap {
+            img_tex: ImageTexture::new(img),
+        }
+    }
+    pub fn color(&self, ray: Vec3) -> Vec3 {
+        let zero = Vec3::new(0., 0., 0.);
+        let u = ray.x.atan2(ray.z) / f32::consts::PI /2.0 + 0.5;
+        let v = ray.y / 2.0 + 0.5;
+        self.img_tex.value(u, v, zero)
+    }
+}

rtiow/renderer/src/texture/image.rs

@@ -0,0 +1,48 @@
+use image::RgbImage;
+
+use crate::texture::Texture;
+use crate::vec3::Vec3;
+
+#[derive(Debug)]
+pub struct ImageTexture {
+    img: RgbImage,
+    width: f32,
+    height: f32,
+}
+
+impl ImageTexture {
+    pub fn new(img: RgbImage) -> ImageTexture {
+        let (w, h) = img.dimensions();
+        ImageTexture {
+            img,
+            width: f32::from(w.min(64000) as u16),
+            height: f32::from(h.min(64000) as u16),
+        }
+    }
+}
+
+impl Texture for ImageTexture {
+    fn value(&self, u: f32, v: f32, _p: Vec3) -> Vec3 {
+        // Wrap texcoords by default.
+        let x = (u % 1. * (self.width - 1.)) as u32;
+        let y = ((1. - v % 1.) * (self.height - 1.)) as u32;
+        if x >= self.width as u32 {
+            panic!(format!(
+                "u {} v {} x {} y {} w {} h {}",
+                u, v, x, y, self.width, self.height
+            ));
+        }
+        if y >= self.height as u32 {
+            panic!(format!(
+                "u {} v {} x {} y {} w {} h {}",
+                u, v, x, y, self.width, self.height
+            ));
+        }
+        let pixel = self.img.get_pixel(x, y);
+        Vec3::new(
+            f32::from(pixel[0]) / 255.,
+            f32::from(pixel[1]) / 255.,
+            f32::from(pixel[2]) / 255.,
+        )
+    }
+}

rtiow/renderer/src/texture/mandelbrot.rs

@@ -0,0 +1,79 @@
+#![allow(clippy::many_single_char_names)]
+use rand;
+use rand::Rng;
+
+use crate::texture::Texture;
+use crate::vec3::Vec3;
+
+#[derive(Debug)]
+pub struct Mandelbrot {
+    scale: f32,
+    palette: Vec<Vec3>,
+}
+
+// HSV values in [0..1]
+// returns [r, g, b] values from 0 to 255
+//From https://martin.ankerl.com/2009/12/09/how-to-create-random-colors-programmatically/
+fn hsv_to_rgb(h: f32, s: f32, v: f32) -> Vec3 {
+    let h_i = (h * 6.) as i32;
+    let f = h * 6. - h_i as f32;
+    let p = v * (1. - s);
+    let q = v * (1. - f * s);
+    let t = v * (1. - (1. - f) * s);
+    match h_i {
+        0 => Vec3::new(v, t, p),
+        1 => Vec3::new(q, v, p),
+        2 => Vec3::new(p, v, t),
+        3 => Vec3::new(p, q, v),
+        4 => Vec3::new(t, p, v),
+        5 => Vec3::new(v, p, q),
+        _ => panic!(format!("Unknown H value {}", h_i)),
+    }
+}
+
+fn generate_palette(num: usize) -> Vec<Vec3> {
+    let mut rng = rand::thread_rng();
+    let mut random = || rng.gen_range(0.0, 0.1);
+    // use golden ratio
+    let golden_ratio_conjugate = 0.618_034;
+    let mut h = random();
+    (0..num)
+        .map(|_| {
+            h += golden_ratio_conjugate;
+            h %= 1.0;
+            hsv_to_rgb(h, 0.99, 0.99)
+        })
+        .collect()
+}
+
+impl Default for Mandelbrot {
+    fn default() -> Self {
+        Mandelbrot {
+            scale: 2.0,
+            palette: generate_palette(10),
+        }
+    }
+}
+
+impl Texture for Mandelbrot {
+    fn value(&self, u: f32, v: f32, _p: Vec3) -> Vec3 {
+        // scaled x coordinate of pixel (scaled to lie in the Mandelbrot X scale (-2.5, 1))
+        let x0 = u * 3.5 - 2.5;
+        // scaled y coordinate of pixel (scaled to lie in the Mandelbrot Y scale (-1, 1))
+        let y0 = v * 2.0 - 1.0;
+        let mut x = 0.0;
+        let mut y = 0.0;
+        let mut iteration = 0;
+        let max_iteration = 1000;
+        while (x * x + y * y) <= 2. * 2. && iteration < max_iteration {
+            let xtemp = x * x - y * y + x0;
+            y = 2. * x * y + y0;
+            x = xtemp;
+            iteration += 1;
+        }
+        if iteration == max_iteration {
+            return Vec3::default();
+        }
+        self.palette[iteration % self.palette.len()]
+    }
+}

rtiow/renderer/src/texture/mod.rs

@@ -0,0 +1,45 @@
+mod checker;
+mod constant;
+mod envmap;
+mod image;
+mod mandelbrot;
+mod noise;
+pub use crate::texture::checker::CheckerTexture;
+pub use crate::texture::constant::ConstantTexture;
+pub use crate::texture::envmap::EnvMap;
+pub use crate::texture::image::ImageTexture;
+pub use crate::texture::mandelbrot::Mandelbrot;
+pub use crate::texture::noise::NoiseTexture;
+
+use std::sync::Arc;
+
+use crate::vec3::Vec3;
+
+pub trait Texture: Send + Sync {
+    fn value(&self, u: f32, v: f32, p: Vec3) -> Vec3;
+}
+
+impl Texture for Arc<dyn Texture> {
+    fn value(&self, u: f32, v: f32, p: Vec3) -> Vec3 {
+        (**self).value(u, v, p)
+    }
+}
+
+impl Texture for Box<dyn Texture> {
+    fn value(&self, u: f32, v: f32, p: Vec3) -> Vec3 {
+        (**self).value(u, v, p)
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn constant_texture_from_array() {
+        assert_eq!(
+            ConstantTexture::new(Vec3::new(1., 2., 3.)),
+            ConstantTexture::new([1., 2., 3.])
+        );
+    }
+}

rtiow/renderer/src/texture/noise.rs

@@ -0,0 +1,46 @@
+use crate::noise::NoiseSource;
+use crate::noise::NoiseType;
+use crate::texture::Texture;
+use crate::vec3::Vec3;
+
+pub struct NoiseTexture<N>
+where
+    N: NoiseSource,
+{
+    noise_source: N,
+    noise_type: NoiseType,
+}
+
+impl<N> NoiseTexture<N>
+where
+    N: NoiseSource,
+{
+    pub fn new(noise_source: N, noise_type: NoiseType) -> NoiseTexture<N> {
+        NoiseTexture {
+            noise_source,
+            noise_type,
+        }
+    }
+}
+
+impl<N> Texture for NoiseTexture<N>
+where
+    N: NoiseSource,
+{
+    fn value(&self, _u: f32, _v: f32, p: Vec3) -> Vec3 {
+        let v = match self.noise_type {
+            NoiseType::Scale(scale) => self.noise_source.scaled(p, scale),
+
+            NoiseType::Turbulence(turbulence) => self.noise_source.turbulence(p, turbulence),
+            NoiseType::Marble {
+                period,
+                power,
+                size,
+                scale,
+            } => self.noise_source.marble(p, period, power, size, scale),
+        };
+        debug_assert!(v >= 0., "Cold pixel @ {}: {}", p, v);
+        debug_assert!(v <= 1., "Hot pixel @ {}: {}", p, v);
+        Vec3::new(1., 1., 1.) * v
+    }
+}

rtiow/renderer/src/translate.rs

@@ -0,0 +1,54 @@
+use crate::aabb::AABB;
+use crate::hitable::Hit;
+use crate::hitable::HitRecord;
+use crate::ray::Ray;
+use crate::vec3::Vec3;
+
+pub struct Translate<H>
+where
+    H: Hit,
+{
+    hitable: H,
+    offset: Vec3,
+}
+
+impl<H> Translate<H>
+where
+    H: Hit,
+{
+    pub fn new<V>(hitable: H, offset: V) -> Translate<H>
+    where
+        V: Into<Vec3>,
+    {
+        Translate {
+            hitable,
+            offset: offset.into(),
+        }
+    }
+}
+
+impl<H> Hit for Translate<H>
+where
+    H: Hit,
+{
+    fn hit(&self, r: Ray, t_min: f32, t_max: f32) -> Option<HitRecord> {
+        let moved_r = Ray::new(r.origin - self.offset, r.direction, r.time);
+        if let Some(rec) = self.hitable.hit(moved_r, t_min, t_max) {
+            return Some(HitRecord {
+                p: rec.p + self.offset,
+                ..rec
+            });
+        }
+        None
+    }
+
+    fn bounding_box(&self, t_min: f32, t_max: f32) -> Option<AABB> {
+        if let Some(bbox) = self.hitable.bounding_box(t_min, t_max) {
+            return Some(AABB::new(
+                bbox.min() + self.offset,
+                bbox.max() + self.offset,
+            ));
+        }
+        None
+    }
+}

rtiow/renderer/src/vec3.rs

@@ -0,0 +1,279 @@
+use std::convert::From;
+use std::fmt;
+use std::num::ParseFloatError;
+use std::ops::Add;
+use std::ops::Div;
+use std::ops::Index;
+use std::ops::Mul;
+use std::ops::Neg;
+use std::ops::Sub;
+use std::str;
+
+use serde_derive::Deserialize;
+use serde_derive::Serialize;
+
+#[derive(Default, Debug, Deserialize, Serialize, PartialEq, Copy, Clone)]
+pub struct Vec3 {
+    pub x: f32,
+    pub y: f32,
+    pub z: f32,
+}
+
+pub fn cross(v1: Vec3, v2: Vec3) -> Vec3 {
+    Vec3 {
+        x: v1.y * v2.z - v1.z * v2.y,
+        y: v1.z * v2.x - v1.x * v2.z,
+        z: v1.x * v2.y - v1.y * v2.x,
+    }
+}
+
+pub fn dot(v1: Vec3, v2: Vec3) -> f32 {
+    v1.x * v2.x + v1.y * v2.y + v1.z * v2.z
+}
+
+impl Vec3 {
+    pub fn new(x: f32, y: f32, z: f32) -> Vec3 {
+        Vec3 { x, y, z }
+    }
+
+    pub fn min(self) -> f32 {
+        self.x.min(self.y).min(self.z)
+    }
+
+    pub fn max(self) -> f32 {
+        self.x.max(self.y).max(self.z)
+    }
+
+    pub fn length(self) -> f32 {
+        self.squared_length().sqrt()
+    }
+
+    pub fn squared_length(self) -> f32 {
+        self.x * self.x + self.y * self.y + self.z * self.z
+    }
+
+    pub fn unit_vector(self) -> Vec3 {
+        self / self.length()
+    }
+
+    pub fn make_unit_vector(&mut self) {
+        *self = self.unit_vector();
+    }
+}
+
+impl From<[f32; 3]> for Vec3 {
+    fn from(v: [f32; 3]) -> Self {
+        Vec3 {
+            x: v[0],
+            y: v[1],
+            z: v[2],
+        }
+    }
+}
+
+impl fmt::Display for Vec3 {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{} {} {}", self.x, self.y, self.z)
+    }
+}
+
+impl str::FromStr for Vec3 {
+    type Err = ParseFloatError;
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let coords: Vec<&str> = s.split(' ').collect();
+        Ok(Vec3 {
+            x: coords[0].parse::<f32>()?,
+            y: coords[1].parse::<f32>()?,
+            z: coords[2].parse::<f32>()?,
+        })
+    }
+}
+
+impl Add<f32> for Vec3 {
+    type Output = Vec3;
+
+    fn add(self, r: f32) -> Vec3 {
+        Vec3 {
+            x: self.x + r,
+            y: self.y + r,
+            z: self.z + r,
+        }
+    }
+}
+
+impl Add for Vec3 {
+    type Output = Vec3;
+
+    fn add(self, r: Vec3) -> Vec3 {
+        Vec3 {
+            x: self.x + r.x,
+            y: self.y + r.y,
+            z: self.z + r.z,
+        }
+    }
+}
+
+impl Div<Vec3> for f32 {
+    type Output = Vec3;
+
+    fn div(self, r: Vec3) -> Vec3 {
+        Vec3 {
+            x: self / r.x,
+            y: self / r.y,
+            z: self / r.z,
+        }
+    }
+}
+
+impl Div<f32> for Vec3 {
+    type Output = Vec3;
+
+    fn div(self, r: f32) -> Vec3 {
+        Vec3 {
+            x: self.x / r,
+            y: self.y / r,
+            z: self.z / r,
+        }
+    }
+}
+
+impl Index<usize> for Vec3 {
+    type Output = f32;
+    fn index(&self, idx: usize) -> &f32 {
+        match idx {
+            0 => &self.x,
+            1 => &self.y,
+            2 => &self.z,
+            _ => panic!(format!("idx {} out of range for vec3", idx)),
+        }
+    }
+}
+
+impl Mul for Vec3 {
+    type Output = Vec3;
+
+    fn mul(self, r: Vec3) -> Vec3 {
+        Vec3 {
+            x: self.x * r.x,
+            y: self.y * r.y,
+            z: self.z * r.z,
+        }
+    }
+}
+
+impl Mul<Vec3> for f32 {
+    type Output = Vec3;
+
+    fn mul(self, v: Vec3) -> Vec3 {
+        Vec3 {
+            x: v.x * self,
+            y: v.y * self,
+            z: v.z * self,
+        }
+    }
+}
+
+impl Mul<f32> for Vec3 {
+    type Output = Vec3;
+
+    fn mul(self, r: f32) -> Vec3 {
+        Vec3 {
+            x: self.x * r,
+            y: self.y * r,
+            z: self.z * r,
+        }
+    }
+}
+
+impl Neg for Vec3 {
+    type Output = Vec3;
+
+    fn neg(self) -> Vec3 {
+        -1. * self
+    }
+}
+
+impl Sub for Vec3 {
+    type Output = Vec3;
+
+    fn sub(self, r: Vec3) -> Vec3 {
+        Vec3 {
+            x: self.x - r.x,
+            y: self.y - r.y,
+            z: self.z - r.z,
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::f32::consts::PI;
+    use std::str::FromStr;
+
+    use super::*;
+
+    #[test]
+    fn vec_add() {
+        let v0 = Vec3::new(1., 2., 3.);
+        let v1 = Vec3::new(1., 1., 1.);
+        assert_eq!(v0 + v1, Vec3::new(2., 3., 4.));
+    }
+
+    #[test]
+    fn vec_div() {
+        let v0 = Vec3::new(1., 2., 4.);
+        assert_eq!(v0 / 2., Vec3::new(0.5, 1., 2.));
+    }
+
+    #[test]
+    fn vec_mul() {
+        let v0 = Vec3::new(1., 2., 4.);
+        assert_eq!(v0 * 0.5, Vec3::new(0.5, 1., 2.));
+        assert_eq!(v0 * v0, Vec3::new(1., 4., 16.));
+    }
+
+    #[test]
+    fn vec_sub() {
+        let v0 = Vec3::new(1., 2., 3.);
+        let v1 = Vec3::new(1., 1., 1.);
+        assert_eq!(v0 - v1, Vec3::new(0., 1., 2.));
+    }
+
+    #[test]
+    fn vec_idx() {
+        let v0 = Vec3::new(1., 2., 3.);
+        assert_eq!(v0[2], 3.);
+    }
+
+    #[test]
+    fn vec_display() {
+        let v0 = Vec3::new(1., 2., 3.);
+        assert_eq!(format!("{}", v0), "1 2 3".to_owned());
+    }
+
+    #[test]
+    fn vec_from_str() {
+        assert_eq!(Vec3::from_str("1. 2. 3.").unwrap(), Vec3::new(1., 2., 3.));
+    }
+
+    #[test]
+    fn vec_str_roundtrip() {
+        let v = Vec3::from_str("1 2 3").unwrap();
+        let s = format!("{}", v);
+        assert_eq!(v, Vec3::from_str(&s).unwrap());
+    }
+
+    #[test]
+    fn vec_dot() {
+        let v0 = Vec3::new(1., 0., 0.);
+        let v1 = Vec3::new(-1., 0., 0.);
+        assert_eq!(dot(v0, v1), v0.length() * v1.length() * PI.cos());
+    }
+
+    #[test]
+    fn vec_cross() {
+        let v0 = Vec3::new(1., 0., 0.);
+        let v1 = Vec3::new(0., 1., 0.);
+        assert_eq!(cross(v0, v1), Vec3::new(0., 0., 1.));
+    }
+}