Add eval to visualizer and fix pbr error

Cargo.lock

@@ -1,6 +1,6 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
-version = 3
+version = 4
 
 [[package]]
 name = "ab_glyph"
@@ -2205,7 +2205,7 @@ dependencies = [
 ]
 
 [[package]]
-name = "ray-tracing-material-validator"
+name = "ray-tracing-material-visualizer"
 version = "0.1.0"
 dependencies = [
  "plotters",

ray-tracing-core/src/material.rs

@@ -8,7 +8,7 @@ pub trait Material<R: Rng>: Sync + Debug {
     fn sample(&self, w_in: Dir3, rng: &mut R) -> SampleResult {
         let w_out = Dir3::sample_cosine_hemisphere(rng);
 
-        SampleResult::new(w_out, self.eval(w_in, w_out, rng))
+        SampleResult::new(w_out, self.eval(w_in, w_out, rng) * FloatConsts::PI)
     }
 }
 

ray-tracing-core/src/math/dir3.rs

@@ -68,6 +68,13 @@ impl Dir3 {
         Dir3::new(Float::sin(phi) * r, Float::cos(theta), Float::cos(phi) * r)
     }
 
+    pub fn sample_uniform_sphere<R: Rng>(rng: &mut R) -> Self {
+        let theta = Float::acos(1.0 - 2.0 * rng.gen::<Float>());
+        let phi = 2.0 * FloatConsts::PI * rng.gen::<Float>();
+        let r = Float::sin(theta);
+        Dir3::new(Float::sin(phi) * r, Float::cos(theta), Float::cos(phi) * r)
+    }
+
     pub fn sample_cosine_hemisphere<R: Rng>(rng: &mut R) -> Self {
         let mut d = Self::sample_disc(rng);
         d.y = Float::sqrt(Float::max(0.0, 1.0 - d.x * d.x - d.z * d.z));

ray-tracing-material-visualizer/Cargo.toml

@@ -1,5 +1,5 @@
 [package]
-name = "ray-tracing-material-validator"
+name = "ray-tracing-material-visualizer"
 version = "0.1.0"
 edition = "2021"
 

ray-tracing-material-visualizer/src/bin/plot.rs

@@ -1,13 +0,0 @@
-use ray_tracing_core::color::Color;
-use ray_tracing_material::{diffuse::DiffuseMaterial, mirror::Mirror};
-use ray_tracing_material_validator::generate_chart;
-
-fn main() -> Result<(), Box<dyn std::error::Error>> {
-    let m = Mirror::new(Color::new(1.0, 1.0, 0.5));
-    generate_chart("mirror.png", &m, 2)?;
-
-    let m = DiffuseMaterial::new(Color::new(1.0, 1.0, 0.5));
-    generate_chart("diffuse.png", &m, 100)?;
-
-    Ok(())
-}

ray-tracing-material-visualizer/src/main.rs

@@ -1,51 +1,68 @@
-use plotters::{coord::Shift, prelude::*};
+use plotters::{
+    chart::ChartBuilder,
+    coord::Shift,
+    prelude::{BitMapBackend, DrawingArea, DrawingBackend, IntoDrawingArea},
+    style::WHITE,
+};
 use rand::{rngs::SmallRng, SeedableRng};
-use ray_tracing_core::{color::Color, prelude::*};
+use ray_tracing_core::prelude::*;
-use rayon::prelude::*;
+use ray_tracing_material::{diffuse::DiffuseMaterial, mirror::Mirror};
+use rayon::iter::{IntoParallelIterator, ParallelExtend, ParallelIterator};
 
-pub fn generate_chart<M: Material<SmallRng>>(
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let w_in = Dir3::new(1.0, 1.0, 0.0).normalize();
+
+    let color = Color::new(1.0, 1.0, 1.0);
+
+    let m = Mirror::new(color);
+    generate_chart("mirror.png", &m, 2, w_in)?;
+
+    let m = DiffuseMaterial::new(color);
+    generate_chart("diffuse.png", &m, 100, w_in)?;
+
+    Ok(())
+}
+
+fn generate_chart<M: Material<SmallRng>>(
     path: impl AsRef<std::path::Path>,
     m: &M,
     samples_per_pixel: usize,
+    w_in: Dir3,
 ) -> Result<(), Box<dyn std::error::Error>> {
     let inner_size = 400;
-    let width = (inner_size + 70) * 3 + 34;
+    let width = (inner_size + 70) * 3;
-    let height = (inner_size + 97) * 2;
+    let height = ((inner_size + 97) * 2 + 32) * 2;
     let root = BitMapBackend::new(&path, (width, height)).into_drawing_area();
-
     root.fill(&WHITE)?;
 
-    let area = root.titled("Sampled", ("sans-serif", 30))?;
+    let executions = inner_size as usize * inner_size as usize * samples_per_pixel;
-    plot_material_sample(&area, m, samples_per_pixel)?;
+
+    let areas = root.split_evenly((2, 1));
+    let eval_histogram = create_histogram_evaled(m, 400, 400, executions, w_in);
+    let sample_histogram = create_historgram_sampled(m, 400, 400, executions, w_in);
+
+    let max = Float::max(eval_histogram.max(), sample_histogram.max());
+    dbg!(max, eval_histogram.max(), sample_histogram.max());
+
+    let area = areas[0].titled("Evaled", ("sans-serif", 30))?;
+    plot_material(&area, eval_histogram, max)?;
+
+    let area = areas[1].titled("Sampled", ("sans-serif", 30))?;
+    plot_material(&area, sample_histogram, max)?;
 
     root.present()?;
 
     Ok(())
 }
 
-fn plot_material_sample<DB: DrawingBackend, M: Material<SmallRng>>(
+fn plot_material<DB: DrawingBackend>(
     root: &DrawingArea<DB, Shift>,
-    m: &M,
+    histogram: Histogram,
-    samples_per_pixel: usize,
+    max: Float,
 ) -> Result<(), Box<dyn std::error::Error>>
 where
     DB::ErrorType: 'static,
 {
-    let (xrange, yrange) = root.get_pixel_range();
-    let width = (xrange.end - xrange.start) as usize;
-    let height = (yrange.end - yrange.start) as usize;
-
-    let width = width / 3 - 70;
-    let height = height / 2 - 97;
-
-    let histogram = create_historgram(
-        m,
-        width,
-        height,
-        samples_per_pixel * width * height,
-        Dir3::new(1.0, 1.0, 0.0).normalize(),
-    );
-
     let areas = root.split_evenly((2, 3));
     for (channel, upper, lower) in (0..3).map(|i| (i, &areas[i], &areas[i + 3])) {
         let channel_name = match channel {
@@ -95,9 +112,17 @@ where
 
         let lower_area = lower_chart.plotting_area();
 
-        let map = ViridisRGB;
+        let (xrange, yrange) = upper_area.get_pixel_range();
+        let width = (xrange.end - xrange.start) as usize;
+        let height = (yrange.end - yrange.start) as usize;
+        assert_eq!(width, histogram.width);
+        assert_eq!(height, histogram.height);
 
-        let max = histogram.max();
+        let (xrange, yrange) = lower_area.get_pixel_range();
+        let width = (xrange.end - xrange.start) as usize;
+        let height = (yrange.end - yrange.start) as usize;
+        assert_eq!(width, histogram.width);
+        assert_eq!(height, histogram.height);
 
         for (dir, f) in histogram.iter() {
             let f = match channel {
@@ -107,7 +132,7 @@ where
                 _ => unreachable!(),
             };
 
-            let color = map.get_color_normalized(f, 0.0, max);
+            let color = plotters::prelude::ViridisRGB::get_color_normalized(f, 0.0, max);
             if dir.y() < 0.0 {
                 lower_area.draw_pixel((dir.x() as f64, dir.z() as f64), &color)?;
             } else {
@@ -139,10 +164,17 @@ impl Histogram {
     }
 
     fn discretize(&self, p: Dir3) -> usize {
-        (((p.x() + 1.0) * 0.5 * self.width as f32).floor() as usize)
+        assert!(p.x() >= -1.0);
-            + (((p.z() + 1.0) * 0.5 * self.height as f32).floor() as usize) * self.width
+        assert!(p.x() <= 1.0);
+        assert!(p.y() >= -1.0);
+        assert!(p.y() <= 1.0);
+        assert!(p.z() >= -1.0);
+        assert!(p.z() <= 1.0);
+        (((p.x() + 1.0) * 0.5 * self.width as f32).floor() as usize).min(self.width - 1)
+            + (((p.z() + 1.0) * 0.5 * self.height as f32).floor() as usize).min(self.height - 1)
+                * self.width
             + if p.y() < 0.0 {
-                2 * self.width * self.height
+                self.width * self.height
             } else {
                 0
             }
@@ -217,7 +249,7 @@ impl ParallelExtend<(Dir3, Color)> for Histogram {
     }
 }
 
-fn create_historgram<M: Material<SmallRng>>(
+fn create_historgram_sampled<M: Material<SmallRng>>(
     m: &M,
     width: usize,
     height: usize,
@@ -237,3 +269,27 @@ fn create_historgram<M: Material<SmallRng>>(
 
     h
 }
+
+fn create_histogram_evaled<M: Material<SmallRng>>(
+    m: &M,
+    width: usize,
+    height: usize,
+    executions: usize,
+    w_in: Dir3,
+) -> Histogram {
+    let mut h = Histogram::new(width, height);
+
+    h.par_extend(
+        (0..executions)
+            .into_par_iter()
+            .map_init(SmallRng::from_entropy, |rng, _| {
+                let w_out = Dir3::sample_uniform_sphere(rng);
+
+                let color = m.eval(w_in, w_out, rng) * w_out.y() * 4.0 * FloatConsts::PI;
+
+                (w_out, color)
+            }),
+    );
+
+    h
+}

ray-tracing-renderer/src/path_tracer.rs

@@ -47,7 +47,7 @@ where
             }
 
             if let Some(material) = i.material() {
-                alpha *= material.eval(w_in, w_out, rng) * w_out.y();
+                alpha *= material.eval(w_in, w_out, rng) * w_out.y() * 2.0 * FloatConsts::PI;
             } else {
                 return sum;
             }

ray-tracing-scene/src/examples/basic_cornell.rs

@@ -64,7 +64,7 @@ pub fn scene<R: Rng + 'static>() -> ExampleScene<R> {
                 },
                 BVHMaterial {
                     material: None,
-                    light: Some(Box::new(AreaLight::new(Color::white() * 30.0))),
+                    light: Some(Box::new(AreaLight::new(Color::white() * 18.0))),
                 },
                 BVHMaterial {
                     material: Some(Box::new(Mirror::new(Color::new(1.0, 1.0, 1.0)))),

ray-tracing-scene/src/examples/cornell2.rs

@@ -24,7 +24,7 @@ pub fn scene<R: Rng + Debug + 'static>() -> ExampleScene<R> {
             .iter()
             .map(|m| match m.name.as_str() {
                 "white" => BVHMaterial::new_material(DiffuseMaterial::new(Color::white())),
-                "light" => BVHMaterial::new_light(AreaLight::new(Color::white() * 100.0)),
+                "light" => BVHMaterial::new_light(AreaLight::new(Color::white() * 30.0)),
                 "blue" => {
                     BVHMaterial::new_material(DiffuseMaterial::new(Color::new(0.0, 0.0, 1.0)))
                 }

ray-tracing-scene/src/examples/stanford_dragon.rs

@@ -21,7 +21,7 @@ pub fn scene<R: Rng + Debug + 'static>() -> ExampleScene<R> {
 
         let materials = vec![
             BVHMaterial::new_material(DiffuseMaterial::new(Color::new(0.2, 0.2, 0.9))),
-            BVHMaterial::new_light(AreaLight::new(Color::white() * 100.0)),
+            BVHMaterial::new_light(AreaLight::new(Color::white() * 30.0)),
         ];
 
         let mut vertices = obj.vertices;