Print out args at start.

rtiow/src/bin/tracer.rs

@@ -122,6 +122,7 @@ fn main() -> Result<(), std::io::Error> {
         .unwrap();
     let start_time: DateTime<Utc> = Utc::now();
     let opt = Opt::from_args();
+    info!("{:?}", opt);
     let scene = opt.model.scene(&opt);
     fs::create_dir_all(&opt.output)?;
     if opt.pprof.is_some() && !cfg!(feature = "profile") {