EaseInOutExpo inside the box.

resources/shader/compute-sample.wgsl

@@ -6,7 +6,7 @@ const kYup = vec3f(0.0, 1.0, 0.0);
 const kRayDepth = 5;
 const kRayMin = 1e-6;
 const kRayMax = 1e20;
-const kSPP = 150;
+const kSPP = 10;
 const kZero = vec3f(0.0, 0.0, 0.0);
 const kOne = vec3f(1.0, 1.0, 1.0);
 
@@ -70,6 +70,8 @@ struct Sphere {
 struct SphereLights {
   l1 : Sphere,
   l2 : Sphere,
+  l3 : Sphere,
+  l4 : Sphere,
 }
 
 fn fabs(x: f32) -> f32 {
@@ -161,13 +163,24 @@ fn sample_direction(hit: HitInfo) -> vec3f {
 }
 
 fn sample_from_light(hit: HitInfo) -> vec3f {
-  // MEMO: 今はSphereLightのみ
+  // FIXME: 境界が目立つ
   // ヒット位置とライト位置を比較
-  let l1_dist = distance(hit.pos, sphere_lights.l1.center);
+  var dist = distance(hit.pos, sphere_lights.l1.center);
+  var sphere = sphere_lights.l1;
   let l2_dist = distance(hit.pos, sphere_lights.l2.center);
-  var sphere = sphere_lights.l2;
-  if (l1_dist < l2_dist) {
-    sphere = sphere_lights.l1;
+  let l3_dist = distance(hit.pos, sphere_lights.l3.center);
+  let l4_dist = distance(hit.pos, sphere_lights.l4.center);
+  if (l2_dist < dist) {
+    dist = l2_dist;
+    sphere = sphere_lights.l2;
+  }
+  if (l3_dist < dist) {
+    dist = l3_dist;
+    sphere = sphere_lights.l3;
+  }
+  if (l4_dist < dist) {
+    dist = l4_dist;
+    sphere = sphere_lights.l4;
   }
   return sample_from_sphere(sphere, hit.pos);
 }
@@ -201,11 +214,21 @@ fn sample_from_cosine(hit: HitInfo) -> vec3f {
 }
 
 fn mixture_pdf(hit: HitInfo, dir: vec3f) -> f32 {
+  /// FIXME: 暗くなってしまう
   let l1_dist = distance(hit.pos, sphere_lights.l1.center);
   let l2_dist = distance(hit.pos, sphere_lights.l2.center);
-  let l1_w = l2_dist / (l1_dist + l2_dist);
-  let l2_w = l1_dist / (l1_dist + l2_dist);
-  return 0.5 * cosine_pdf(hit, dir) + 0.5 * (l1_w * sphere_pdf(hit, sphere_lights.l1, dir) + l2_w * sphere_pdf(hit, sphere_lights.l2, dir));
+  let l3_dist = distance(hit.pos, sphere_lights.l3.center);
+  let l4_dist = distance(hit.pos, sphere_lights.l4.center);
+  let dist_sum = l1_dist + l2_dist + l3_dist + l4_dist;
+  let l1_w = (l2_dist + l3_dist + l4_dist) / dist_sum;
+  let l2_w = (l1_dist + l3_dist + l4_dist) / dist_sum;
+  let l3_w = (l1_dist + l2_dist + l4_dist) / dist_sum;
+  let l4_w = (l1_dist + l2_dist + l3_dist) / dist_sum;
+  let light_pdf = l1_w * sphere_pdf(hit, sphere_lights.l1, dir) +
+                  l2_w * sphere_pdf(hit, sphere_lights.l2, dir) +
+                  l3_w * sphere_pdf(hit, sphere_lights.l3, dir) +
+                  l4_w * sphere_pdf(hit, sphere_lights.l4, dir);
+  return 0.5 * cosine_pdf(hit, dir) + 0.5 * light_pdf;
 }
 
 fn sphere_pdf(hit: HitInfo, sphere: Sphere, dir: vec3f) -> f32 {
@@ -260,9 +283,8 @@ fn raytrace(path: Path, depth: i32) -> Path {
   if (emissive) {
     if (depth == 0) {
       var light_col = hit.col / length(hit.col);
-      let vdotn = dot(-r.dir.xyz, hit.norm.xyz);
-      // TODO: 正しい計算&Bloom...?
-      light_col = light_col + light_col * schlick_fresnel(vec3f(0.02), vdotn);
+      let dist = distance(camera.start.xyz, hit.pos.xyz);
+      light_col = hit.col / max(dist * dist, 1.0);
       return Path(r, light_col, true);
     }
     // 照明計算
@@ -299,6 +321,8 @@ fn sample_hit(r: Ray) -> HitInfo {
   // 光源との交差判定
   hit = intersect_sphere(r, sphere_lights.l1, hit);
   hit = intersect_sphere(r, sphere_lights.l2, hit);
+  hit = intersect_sphere(r, sphere_lights.l3, hit);
+  hit = intersect_sphere(r, sphere_lights.l4, hit);
   return hit;
 }
 

src/camera.cpp

@@ -60,11 +60,12 @@ void Camera::InitBindGroup(Device &device) {
 }
 
 void Camera::Update(Queue &queue, float t, float aspect) {
-  float move_dist = lerp(0.0, 40.0, t);
+  t = EaseInOutExpo(t);
+  float move_dist = Lerp(0.0, 40.0, t);
+  float fovy = t < 0.5 ? Lerp(40, 90, t / 0.5f) : Lerp(90, 40, (t - 0.5f) / 0.5f);
   Point3 origin = Vec3(0, 0, 0.01f - move_dist);
   Point3 target = Vec3(0, 0, 15 + move_dist);
   float time = 0.0f;
-  float fovy = 90.0f;
   CameraParam param(origin, target, aspect, fovy, time, RandSeed());
   queue.writeBuffer(uniform_buffer_, 0, &param, sizeof(CameraParam));
 }

src/include/renderer.h

@@ -42,7 +42,7 @@ class Renderer {
 private:
     static const uint32_t WIDTH = 640;
     static const uint32_t HEIGHT = 480;
-    static const uint32_t MAX_FRAME = 1;
+    static const uint32_t MAX_FRAME = 300;
     Camera camera_{};
     Scene scene_{};
     bool hasWindow_ = false;

src/include/scene.h

@@ -21,8 +21,10 @@ class Scene {
     struct SphereLights {
         Sphere l1_;
         Sphere l2_;
+        Sphere l3_;
+        Sphere l4_;
 
-        SphereLights(Sphere l1, Sphere l2) : l1_(l1), l2_(l2) {};
+        SphereLights(Sphere l1, Sphere l2, Sphere l3, Sphere l4) : l1_(l1), l2_(l2), l3_(l3), l4_(l4) {};
     };
 
     void Release();
@@ -46,6 +48,10 @@ class Scene {
 
     void InitBindGroup(Device &device);
 
+    size_t inline GetSphereLightsNum() {
+      return sizeof(SphereLights) / sizeof(Sphere);
+    };
+
 public:
     std::vector<Triangle> tris_;
     std::vector<Quad> quads_;

src/include/utils/util.h

@@ -59,6 +59,17 @@ inline int RandInt(int min, int max) {
 }
 
 // 線形補間
-inline float lerp(float a, float b, float t) {
+inline float Lerp(float a, float b, float t) {
   return a + t * (b - a);
+}
+
+inline float EaseInQuart(float t) {
+  return t * t * t * t;
+}
+
+inline float EaseInOutExpo(float t) {
+  if (t == 0 || t == 1) {
+    return t;
+  }
+  return t < 0.5 ? pow(2.0f, 20.0f * t - 10.0f) / 2.0f : (2.0f - pow(2.0f, -20.0f * t + 10.0f)) / 2.0f;
 }

src/render.cpp

@@ -68,8 +68,8 @@ bool Renderer::InitDevice() {
   // Setting up required limits
   RequiredLimits requiredLimits = Default;
   requiredLimits.limits.maxBindGroups = 3;
-  requiredLimits.limits.maxUniformBuffersPerShaderStage = 1;
-  requiredLimits.limits.maxUniformBufferBindingSize = 16 * sizeof(float);
+  requiredLimits.limits.maxUniformBuffersPerShaderStage = 2;
+  requiredLimits.limits.maxUniformBufferBindingSize = sizeof(Scene::SphereLights);
   // origin(3), target(3), aspect(1), time(1), seed(1)
   // Without this, wgpu-native crashes
   requiredLimits.limits.maxVertexAttributes = 3;

src/scene.cpp

@@ -18,7 +18,7 @@ Scene::Scene(Device &device) {
   cb.PushToQuads(quads_);
 
   /// Sphereの追加
-  spheres_.emplace_back(Point3(-1.0, 0, -9), 0.3, Color3(0.0, 0.2, 0.5));
+  spheres_.emplace_back(Point3(-1.0, 0, -9), 0.3, Color3(0.8, 0.8, 0.8));
   /// バッファのバインド
   InitBindGroupLayout(device);
   InitBuffers(device);
@@ -151,7 +151,7 @@ void Scene::InitBindGroupLayout(Device &device) {
 void Scene::InitBuffers(Device &device) {
   quad_buffer_ = CreateQuadBuffer(device);
   sphere_buffer_ = CreateSphereBuffer(device, spheres_.size(), BufferUsage::Storage, true);
-  sphere_light_buffer_ = CreateSphereBuffer(device, 2, BufferUsage::Uniform | BufferUsage::CopyDst, false);
+  sphere_light_buffer_ = CreateSphereBuffer(device, GetSphereLightsNum(), BufferUsage::Uniform | BufferUsage::CopyDst, false);
 }
 
 /*
@@ -328,10 +328,10 @@ void Scene::InitBindGroup(Device &device) {
  * SphereLightの更新
  */
 void Scene::UpdateSphereLights(Queue &queue, float t) {
-  Sphere l1(Point3(0, 0, -40), 0.5, Color3(20, 20, 20), true);
-  auto x = lerp(-2.0, 2.0, t);
-  auto z = lerp(0.0, 30.0, t);
-  Sphere l2(Point3(x, 1.0, -10 - z), 0.3, Color3(20, 150 + 30.0f * t, 20), true);
-  SphereLights lights(l1, l2);
+  Sphere l1(Point3(0, 0, -50), 0.5, Color3(2000, 2000, 2000), true);
+  Sphere l2(Point3(1.0, 2.0, -10), 0.3, Color3(20, 1500, 20), true);
+  Sphere l3(Point3(0.0, 2.0, -20), 0.3, Color3(1500, 20, 20), true);
+  Sphere l4(Point3(-1.0, 2.0, -30), 0.3, Color3(20, 20, 1500), true);
+  SphereLights lights(l1, l2, l3, l4);
   queue.writeBuffer(sphere_light_buffer_, 0, &lights, sizeof(SphereLights));
 }