Basic Perlin texture implementation.

rtiow/Cargo.lock

@@ -490,6 +490,7 @@ dependencies = [
  "cpuprofiler 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "crossbeam-channel 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "image 0.19.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "num_cpus 1.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.5.5 (registry+https://github.com/rust-lang/crates.io-index)",

rtiow/Cargo.toml

@@ -13,6 +13,7 @@ structopt = "0.2.10"
 stderrlog = "0.4.1"
 log = "0.4.5"
 cpuprofiler = "0.0.3"
+lazy_static = "1.1.0"
 
 # For better profiling support.
 [profile.release]

rtiow/src/lib.rs

@@ -7,6 +7,7 @@ pub mod hitable_list;
 pub mod kdtree;
 pub mod material;
 pub mod moving_sphere;
+pub mod perlin;
 pub mod ray;
 pub mod renderer;
 pub mod scenes;
@@ -17,6 +18,8 @@ pub mod vec3;
 extern crate crossbeam_channel;
 extern crate image;
 #[macro_use]
+extern crate lazy_static;
+#[macro_use]
 extern crate log;
 extern crate num_cpus;
 extern crate rand;

rtiow/src/perlin.rs

@@ -0,0 +1,98 @@
+use rand;
+use rand::Rng;
+//use rand::SeedableRng;
+//use rand::XorShiftRng;
+
+use vec3::Vec3;
+
+lazy_static! {
+    pub static ref GENERATOR: Perlin = Perlin::new();
+}
+//const SEED: [u8; 16] = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15];
+
+pub struct Perlin {
+    ranfloat: Vec<f32>,
+    perm_x: Vec<usize>,
+    perm_y: Vec<usize>,
+    perm_z: Vec<usize>,
+}
+
+fn perlin_generate() -> Vec<f32> {
+    //let mut rng: XorShiftRng = SeedableRng::from_seed(SEED);
+    let mut rng = rand::thread_rng();
+    (0..256).map(|_| rng.gen_range::<f32>(0., 1.)).collect()
+}
+
+fn permute(p: &mut Vec<usize>, n: usize) {
+    //let mut rng: XorShiftRng = SeedableRng::from_seed(SEED);
+    let mut rng = rand::thread_rng();
+    let mut random = || rng.gen_range::<f32>(0., 1.);
+    for i in (0..n).rev() {
+        let target = (random() * (i + 1) as f32) as usize;
+        let tmp = p[i];
+        p[i] = p[target];
+        p[target] = tmp;
+    }
+}
+
+fn perlin_generate_perm() -> Vec<usize> {
+    let mut p: Vec<usize> = (0..256).map(|i| i).collect();
+    permute(p.as_mut(), 256);
+    p
+}
+
+fn trilinear_interp(c: [[[f32; 2]; 2]; 2], u: f32, v: f32, w: f32) -> f32 {
+    let mut accum = 0.;
+    for i in 0..2 {
+        for j in 0..2 {
+            for k in 0..2 {
+                let fi = i as f32;
+                let fj = j as f32;
+                let fk = k as f32;
+                accum += (fi * u + (1. - fi) * (1. - u))
+                    * (fj * v + (1. - fj) * (1. - v))
+                    * (fk * w + (1. - fk) * (1. - w))
+                    * c[i][j][k];
+            }
+        }
+    }
+    accum
+}
+
+impl Perlin {
+    fn new() -> Perlin {
+        Perlin {
+            ranfloat: perlin_generate(),
+            perm_x: perlin_generate_perm(),
+            perm_y: perlin_generate_perm(),
+            perm_z: perlin_generate_perm(),
+        }
+    }
+
+    pub fn noise(&self, p: Vec3) -> f32 {
+        let mut u = p.x - p.x.floor();
+        let mut v = p.y - p.y.floor();
+        let mut w = p.z - p.z.floor();
+
+        // Hermite cubic to round off interpolation and attempt to address 'mach bands'.
+        u = u * u * (3. - 2. * u);
+        v = v * v * (3. - 2. * v);
+        w = w * w * (3. - 2. * w);
+
+        let i = p.x.floor() as usize;
+        let j = p.y.floor() as usize;
+        let k = p.z.floor() as usize;
+
+        let mut c: [[[f32; 2]; 2]; 2] = Default::default();
+        for di in 0..2 {
+            for dj in 0..2 {
+                for dk in 0..2 {
+                    c[di][dj][dk] = self.ranfloat[self.perm_x[(i + di) & 255]
+                                                      ^ self.perm_y[(j + dj) & 255]
+                                                      ^ self.perm_z[(k + dk) & 255]]
+                }
+            }
+        }
+        trilinear_interp(c, u, v, w)
+    }
+}

rtiow/src/renderer.rs

@@ -76,7 +76,7 @@ pub struct Opt {
     #[structopt(short = "h", long = "height", default_value = "1024")]
     pub height: usize,
     /// Sub-samples per pixel
-    #[structopt(short = "s", long = "subsample", default_value = "1")]
+    #[structopt(short = "s", long = "subsample", default_value = "8")]
     pub subsamples: usize,
     /// Select scene to render, one of: "bench", "book", "tutorial" "cube", "bvh", "test"
     #[structopt(long = "model", default_value = "test")]

rtiow/src/scenes/test.rs

@@ -1,24 +1,24 @@
-use std::f32::consts::PI;
-
 use camera::Camera;
 use hitable::Hit;
 use hitable_list::HitableList;
 use kdtree::KDTree;
 use material::Lambertian;
+use material::Metal;
+use moving_sphere::MovingSphere;
 use renderer::Opt;
 use renderer::Scene;
 use sphere::Sphere;
-use texture::CheckerTexture;
 use texture::ConstantTexture;
+use texture::NoiseTexture;
 use vec3::Vec3;
 
 pub fn new(opt: &Opt) -> Scene {
-    let lookfrom = Vec3::new(0.001, 0.001, 20.);
+    let lookfrom = Vec3::new(5., 5., 5.);
     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 time_max = 1.;
     let camera = Camera::new(
         lookfrom,
         lookat,
@@ -30,48 +30,52 @@ pub fn new(opt: &Opt) -> Scene {
         time_min,
         time_max,
     );
-    let mut objects: Vec<Box<Hit>> = vec![Box::new(Sphere::new(
+    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 objects: Vec<Box<Hit>> = vec![
+        Box::new(Sphere::new(
             Vec3::new(0., 0., 0.),
-        5.,
-        Box::new(Lambertian::new(Box::new(CheckerTexture::new(
-            Box::new(ConstantTexture::new(Vec3::new(0., 0., 0.))),
-            Box::new(ConstantTexture::new(Vec3::new(1., 1., 1.))),
-        )))),
-    ))];
-    let num_spheres = 6;
-    let radius = 7.;
-    for i in 0..num_spheres {
-        let c1 = radius * ((2. * PI) * (i as f32 / num_spheres as f32)).sin();
-        let c2 = radius * ((2. * PI) * (i as f32 / num_spheres as f32)).cos();
-        let center = Vec3::new(0., c1, c2);
-        objects.push(Box::new(Sphere::new(
-            center,
             0.5,
             Box::new(Lambertian::new(Box::new(ConstantTexture::new(Vec3::new(
-                1., 0., 0.,
+                0.1, 0.2, 0.5,
             ))))),
-        )));
-        let center = Vec3::new(c1, 0., c2);
-        objects.push(Box::new(Sphere::new(
-            center,
+        )),
+        // Big sphere
+        Box::new(Sphere::new(
+            Vec3::new(0., 0., -2.),
+            1.0,
+            Box::new(Lambertian::new(Box::new(NoiseTexture::with_scale(10.)))),
+        )),
+        // Earth sized sphere
+        Box::new(Sphere::new(
+            Vec3::new(0., -100.5, 0.),
+            100.,
+            // Box::new(Lambertian::new(ground_color)),
+            Box::new(Lambertian::new(Box::new(NoiseTexture::new()))),
+        )),
+        // Shiny sphere
+        Box::new(Sphere::new(
+            Vec3::new(1., 0., 0.),
             0.5,
-            Box::new(Lambertian::new(Box::new(ConstantTexture::new(Vec3::new(
-                0., 1., 0.,
-            ))))),
-        )));
-        let center = Vec3::new(c1, c2, 0.);
-        objects.push(Box::new(Sphere::new(
-            center,
+            Box::new(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.,
             Box::new(Lambertian::new(Box::new(ConstantTexture::new(Vec3::new(
-                0., 0., 1.,
+                0.2, 0.8, 0.2,
             ))))),
-        )));
-    }
+        )),
+    ];
     let world: Box<Hit> = if opt.use_accel {
-        let kd = KDTree::new(objects, time_min, time_max);
-        //println!("{}", kd);
-        Box::new(kd)
+        Box::new(KDTree::new(objects, time_min, time_max))
     } else {
         Box::new(HitableList::new(objects))
     };

rtiow/src/texture.rs

@@ -1,3 +1,4 @@
+use perlin::GENERATOR;
 use vec3::Vec3;
 
 pub trait Texture: Send + Sync {
@@ -41,3 +42,22 @@ impl Texture for CheckerTexture {
         }
     }
 }
+
+pub struct NoiseTexture {
+    scale: f32,
+}
+
+impl NoiseTexture {
+    pub fn new() -> NoiseTexture {
+        NoiseTexture { scale: 1. }
+    }
+    pub fn with_scale(scale: f32) -> NoiseTexture {
+        NoiseTexture { scale }
+    }
+}
+
+impl Texture for NoiseTexture {
+    fn value(&self, _u: f32, _v: f32, p: Vec3) -> Vec3 {
+        Vec3::new(1., 1., 1.) * GENERATOR.noise(self.scale * p)
+    }
+}