🔧 Add tonemapping

tools/eclipse-shadow-generator/with_atmosphere.cu

@@ -59,6 +59,39 @@ cudaTextureObject_t createCudaTexture(tiff_utils::RGBATexture const& texture) {
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 
+// Tonemapping code and color space conversions.
+// http://filmicworlds.com/blog/filmic-tonemapping-operators/
+
+__device__ glm::vec3 uncharted2Tonemap(glm::vec3 c) {
+ const float A = 0.15;
+ const float B = 0.50;
+ const float C = 0.10;
+ const float D = 0.20;
+ const float E = 0.02;
+ const float F = 0.30;
+ return ((c * (A * c + C * B) + D * E) / (c * (A * c + B) + D * F)) - E / F;
+}
+
+__device__ glm::vec3 tonemap(glm::vec3 c) {
+ const float W = 11.2;
+ c = uncharted2Tonemap(10.0f * c);
+ glm::vec3 whiteScale = glm::vec3(1.0) / uncharted2Tonemap(glm::vec3(W));
+ return c * whiteScale;
+}
+
+__device__ float linearToSRGB(float c) {
+ if (c <= 0.0031308f)
+ return 12.92f * c;
+ else
+ return 1.055f * pow(c, 1.0f / 2.4f) - 0.055f;
+}
+
+__device__ glm::vec3 linearToSRGB(glm::vec3 c) {
+ return glm::vec3(linearToSRGB(c.r), linearToSRGB(c.g), linearToSRGB(c.b));
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
 __device__ glm::vec4 texture2D(cudaTextureObject_t tex, glm::vec2 uv) {
  auto data = tex2D<float4>(tex, uv.x, uv.y);
  return glm::vec4(data.x, data.y, data.z, data.w);
@@ -330,17 +363,18 @@ __global__ void drawPlanet(float* shadowMap, ShadowSettings settings, LimbDarken
  }
 
  // Horizon close up from quite close to the Earth.
- glm::dvec3 camera = glm::dvec3(0.0, constants.BOTTOM_RADIUS, 2000000.0);
- double fieldOfView = 0.01 * M_PI;
- glm::dvec3 sunDirection = glm::normalize(glm::vec3(0.0, 0.0, -1.0));
- float exposure = 0.00000001;
-
- // Horizon close up from Moon.
- // glm::dvec3 camera = glm::dvec3(0.0, constants.BOTTOM_RADIUS, 300000000.0);
- // double fieldOfView = 0.005 * M_PI;
+ // glm::dvec3 camera = glm::dvec3(0.0, constants.BOTTOM_RADIUS, 2000000.0);
+ // double fieldOfView = 0.01 * M_PI;
  // glm::dvec3 sunDirection = glm::normalize(glm::vec3(0.0, 0.0, -1.0));
  // float exposure = 0.0001;
 
+ // Horizon close up from Moon.
+ glm::dvec3 camera = glm::dvec3(0.0, constants.BOTTOM_RADIUS, 300000000.0);
+ double fieldOfView = 0.005 * M_PI;
+ glm::dvec3 sunDirection = glm::normalize(glm::vec3(0.0, 0.0, -1.0));
+ float exposure = 0.0001;
+ // float exposure = 0.0000000001;
+
  // Total eclipse from Moon.
  // glm::dvec3 camera = glm::dvec3(0.0, 0.0, 300000000.0);
  // double fieldOfView = 0.018 * M_PI;
@@ -364,16 +398,11 @@ __global__ void drawPlanet(float* shadowMap, ShadowSettings settings, LimbDarken
  transmittanceTexture, multiscatteringTexture, singleScatteringTexture, camera, rayDir,
  sunDirection);
 
- shadowMap[i * 3 + 0] = radiance.r * exposure;
- shadowMap[i * 3 + 1] = radiance.g * exposure;
- shadowMap[i * 3 + 2] = radiance.b * exposure;
+ radiance = linearToSRGB(tonemap(radiance * exposure));
 
- // glm::vec2 uv = glm::vec2(x / float(settings.size),
- // getTextureCoordFromUnitRange(1.0, constants.TRANSMITTANCE_TEXTURE_HEIGHT));
- // glm::vec3 test = glm::vec3(texture2D(thetaDeviationTexture, uv));
- // shadowMap[i * 3 + 0] = test.r * 30;
- // shadowMap[i * 3 + 1] = test.g * 30;
- // shadowMap[i * 3 + 2] = test.b * 30;
+ shadowMap[i * 3 + 0] = radiance.r;
+ shadowMap[i * 3 + 1] = radiance.g;
+ shadowMap[i * 3 + 2] = radiance.b;
 }
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////