Some more adjustments to clouds

common/noise/cloudnoise.cpp

@@ -6,7 +6,7 @@ CloudNoise::CloudNoise(int size) : Noise(size)
 {
     // Some worley noises
     WorleyNoise worleyNoise1(size, 3);
-    WorleyNoise worleyNoise3(size, 8);
+    WorleyNoise worleyNoise3(size, 15);
 
     // Some perlin noises
     PerlinNoise perlinNoise1(size, 3);

fancy1.cpp

@@ -44,11 +44,12 @@ int main()
 
     // Add box for volume shader
     auto cloudSettings = CloudSettings();
-    cloudSettings.scale = 10.0f;
+    cloudSettings.scale = 15.0f;
-    cloudSettings.densityIntensity = 3.0f;
+    cloudSettings.densityIntensity = 10.0f;
-    cloudSettings.densityTreshold = 0.55f;
+    cloudSettings.densityTreshold = 0.49f;
+    cloudSettings.densityAbsorption = 0.9f;
     auto cloudShader = std::make_shared<CloudShader>(cloudSettings);
-    scene.add(std::make_shared<Box>(Vector3d(5.0f, 6.0f, 5.0f), Vector3d(50.0f, 4.0f, 50.0f), cloudShader));
+    scene.add(std::make_shared<Box>(Vector3d(5.0f, 8.0f, 5.0f), Vector3d(50.0f, 5.0f, 50.0f), cloudShader));
 
     // build the tree
     scene.buildTree();

shader/cloudshader.cpp

@@ -1,5 +1,6 @@
 #include "cloudshader.h"
 #include "common/noise/cloudnoise.h"
+#include "common/noise/perlinnoise.h"
 
 
 Color CloudShader::shade(const Scene &scene, const Ray &ray) const
@@ -7,7 +8,6 @@ Color CloudShader::shade(const Scene &scene, const Ray &ray) const
     Vector3d hitPoint = ray.origin + ray.direction * ray.length; // Potentially add epsilon
 
     // Collect getNoise through the cloud
-    float accumulatedNoise = 0.0f;
     float cloudLength = 0.0f;   // Length of cloud in ray direction
 
     // Get background color behind cloud and information about the clouds length
@@ -32,19 +32,22 @@ Color CloudShader::shade(const Scene &scene, const Ray &ray) const
 
     if (cloudLength == 0.0f) return background; // No cloud or at edge
 
-    // Get getNoise through cloud
+    // Calculate step length
-    int const NOISE_SAMPLES = settings.densitySamples;
+    int noiseSamples = settings.densitySamples;
-    float stepWeight = cloudLength / (float) NOISE_SAMPLES;
+    float stepLength = cloudLength / noiseSamples;
-    for (int i = 0; i < NOISE_SAMPLES; ++i)
-    {
-        float progress = (float) i / (float) NOISE_SAMPLES;
-        Vector3d samplePoint = hitPoint + progress * cloudLength * ray.direction;
-        float sampleDensity = getCloudDensity(samplePoint);
-        accumulatedNoise += sampleDensity * stepWeight;
-    }
 
-    // Pre-processs accumulated getNoise
+    // Step through cloud
-    float cloudDensity = exp(-accumulatedNoise * settings.densityAbsorption);
+    float transmittance = 1.0f;
+    for (int i = 0; i < noiseSamples; ++i)
+    {
+        // Get sample point
+        Vector3d samplePoint = hitPoint + i * stepLength * ray.direction;
+
+        // Get data at point
+        float sampleDensity = getCloudDensity(samplePoint) * stepLength;
+
+        transmittance *= exp(-sampleDensity * stepLength * settings.densityAbsorption);
+    }
 
     // Add some ambient and diffuse lighting
 //    cloud += scene.ambientLight() * material.ambient();
@@ -56,7 +59,7 @@ Color CloudShader::shade(const Scene &scene, const Ray &ray) const
 //        cloud += material.cloud() * illumination.cloud * diffuse;
 //    }
 
-    return background * cloudDensity + (1.0f - cloudDensity) * settings.cloudColor;
+    return background * transmittance + (1.0f - transmittance) * settings.cloudColor;
 }
 
 bool CloudShader::isTransparent() const

shader/cloudshader.h

@@ -14,7 +14,7 @@ struct CloudSettings
     float scale = 10;
     float densityTreshold = 0.55f;
     float densityIntensity = 2.5f;
-    float densityAbsorption = 1;
+    float densityAbsorption = 2;
     Color cloudColor = Color(1, 1, 1);
 };