Add MIS Test scene

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

@@ -0,0 +1,175 @@
+use std::cell::OnceCell;
+
+use crate::triangle_bvh::{BVHMaterial, Triangle, TriangleBVH};
+
+use super::ExampleScene;
+
+use ray_tracing_core::{light::AreaLight, prelude::*, scene::Scene};
+use ray_tracing_material::{
+    diffuse::DiffuseMaterial,
+    microfacet::{BeckmannDistribution, Microfacet},
+    mirror::Mirror,
+};
+
+pub struct MISTest<R: Rng> {
+    scene: OnceCell<TriangleBVH<R>>,
+    dist: Float,
+    light_height: Float,
+    camera_height: Float,
+    camera_dist: Float,
+    num_lights: usize,
+    plane_width: Float,
+    plane_depth: Float,
+    light_min: Float,
+    light_max: Float,
+    materials: fn() -> Vec<BVHMaterial<R>>,
+}
+
+impl<R: Rng> MISTest<R> {
+    pub fn new() -> Self {
+        MISTest {
+            scene: OnceCell::new(),
+            dist: 2.0,
+            light_height: 6.0,
+            camera_height: 10.0,
+            camera_dist: 6.0,
+            num_lights: 4,
+            plane_width: 10.0,
+            plane_depth: 0.5,
+            light_min: 0.05,
+            light_max: 0.7,
+            materials: || {
+                vec![
+                    BVHMaterial::new_material(Mirror::new(Color::white())),
+                    BVHMaterial::new_material(Microfacet::new(
+                        BeckmannDistribution::new(0.05),
+                        Color::white(),
+                    )),
+                    BVHMaterial::new_material(Microfacet::new(
+                        BeckmannDistribution::new(0.1),
+                        Color::white(),
+                    )),
+                    BVHMaterial::new_material(Microfacet::new(
+                        BeckmannDistribution::new(0.2),
+                        Color::white(),
+                    )),
+                    BVHMaterial::new_material(Microfacet::new(
+                        BeckmannDistribution::new(0.3),
+                        Color::white(),
+                    )),
+                ]
+            },
+        }
+    }
+
+    fn camera_x(&self) -> Float {
+        -((((self.materials)().len() - 1) as Float) * 0.5 + self.camera_dist)
+    }
+}
+
+impl<R: Rng + 'static> ExampleScene<R> for MISTest<R> {
+    fn get_scene(&self) -> Box<dyn Scene<R> + Sync> {
+        let s = self.scene.get_or_init(move || {
+            let mut vertices = Vec::new();
+            let mut triangles = Vec::new();
+            let mut materials = Vec::new();
+
+            for i in 0..self.num_lights {
+                let center_z = self.dist * ((i as Float) - 0.5 * ((self.num_lights - 1) as Float));
+                let light_offset = 0.5
+                    * (self.light_min
+                        + ((i as Float) / ((self.num_lights - 1) as Float))
+                            * (self.light_max - self.light_min));
+
+                let vertex_offset = vertices.len() as u32;
+                vertices.extend_from_slice(&[
+                    Pos3::new(-light_offset, self.light_height, -light_offset + center_z),
+                    Pos3::new(light_offset, self.light_height, -light_offset + center_z),
+                    Pos3::new(-light_offset, self.light_height, light_offset + center_z),
+                    Pos3::new(light_offset, self.light_height, light_offset + center_z),
+                ]);
+
+                let area = light_offset * light_offset * 4.0;
+                let material_offset = materials.len() as u32;
+                materials.push(BVHMaterial::new_light(AreaLight::new(
+                    Color::white() * 10.0 / area,
+                )));
+
+                triangles.extend_from_slice(&[
+                    Triangle::new(
+                        [vertex_offset, vertex_offset + 1, vertex_offset + 3],
+                        material_offset,
+                    ),
+                    Triangle::new(
+                        [vertex_offset, vertex_offset + 3, vertex_offset + 2],
+                        material_offset,
+                    ),
+                ]);
+            }
+
+            let mats = (self.materials)();
+            let num_materials = mats.len();
+
+            for (i, mat) in mats.into_iter().enumerate() {
+                let center_x = self.dist * ((i as Float) - 0.5 * ((num_materials - 1) as Float));
+
+                let theta_light = Float::atan2(center_x, self.light_height);
+                let theta_camera = Float::atan2(center_x - self.camera_x(), self.camera_height);
+
+                let theta = (theta_camera + theta_light) * 0.5;
+
+                dbg!(
+                    i,
+                    theta_camera.to_degrees(),
+                    theta_light.to_degrees(),
+                    theta.to_degrees()
+                );
+
+                let offset_x = self.plane_depth * Float::cos(theta);
+                let offset_y = self.plane_depth * Float::sin(theta);
+
+                let vertex_offset = vertices.len() as u32;
+                vertices.extend_from_slice(&[
+                    Pos3::new(center_x + offset_x, offset_y, -0.5 * self.plane_width),
+                    Pos3::new(center_x - offset_x, -offset_y, -0.5 * self.plane_width),
+                    Pos3::new(center_x + offset_x, offset_y, 0.5 * self.plane_width),
+                    Pos3::new(center_x - offset_x, -offset_y, 0.5 * self.plane_width),
+                ]);
+
+                let material_offset = materials.len() as u32;
+                materials.push(mat);
+
+                triangles.extend_from_slice(&[
+                    Triangle::new(
+                        [vertex_offset, vertex_offset + 1, vertex_offset + 3],
+                        material_offset,
+                    ),
+                    Triangle::new(
+                        [vertex_offset, vertex_offset + 3, vertex_offset + 2],
+                        material_offset,
+                    ),
+                ]);
+            }
+
+            TriangleBVH::new(vertices, triangles, materials)
+        });
+
+        Box::new(s.clone()) as Box<dyn Scene<R> + Sync>
+    }
+
+    fn get_camera_pos(&self) -> Pos3 {
+        Pos3::new(self.camera_x(), self.camera_height, 0.0)
+    }
+
+    fn get_camera_look_at(&self) -> Pos3 {
+        Pos3::new(0.0, 0.0, 0.0)
+    }
+
+    fn get_camera_up(&self) -> Dir3 {
+        Dir3::up()
+    }
+
+    fn get_horizontal_fov(&self) -> Float {
+        Float::to_radians(90.0)
+    }
+}

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

@@ -27,10 +27,12 @@ pub fn example_scenes<R: Rng + Debug + 'static>() -> HashMap<&'static str, Box<d
         "stanford_dragon_as",
         Box::new(stanford_dragon_as::StanfordDragon::new()),
     );
+    map.insert("mis_test", Box::new(mis_test::MISTest::new()));
     map
 }
 
 pub mod basic_cornell;
 pub mod cornell2;
+pub mod mis_test;
 pub mod stanford_dragon;
 pub mod stanford_dragon_as;