m.giller/cloudy-raytracer
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Clouds still bad

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This commit is contained in:
Maximilian Giller 2023-01-27 05:22:54 +01:00
parent d7c093944d
commit 79446c289b
3 changed files with 38 additions and 26 deletions
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11
fancy1.cpp
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@ -29,9 +29,10 @@ int main()
{
FastScene scene;
scene.setBackgroundColor(Color(0.529f, 0.808f, 0.922f) * 1.0f);
// scene.setBackgroundColor(Color(1, 0.79f, 0.62f) * 0.8f);
// Add lights
auto mainLight = std::make_shared<SunLight>(Vector3d(-1.0f, -0.5f, -1.0f), 5.0f, Color(1, 0.79f, 0.62f));
auto mainLight = std::make_shared<SunLight>(Vector3d(-1.0f, -0.5f, -1.0f), 2.0f, Color(1,1,1));//Color(1, 0.79f, 0.62f));
scene.add(mainLight);
// scene.add(std::make_shared<AmbientLight>(0.3f));
// auto light = std::make_shared<PointLight>(Vector3d(25.0f, 10.0f, 25.0f), 100.0f);
@ -43,10 +44,10 @@ int main()
// busShader);
// Refraction boxes
auto boxShader = std::make_shared<RefractionShader>(1.05f, 1, Color(1,1,0), 0.7f);
scene.add(std::make_shared<Box>(Vector3d(5.0f, 3.0f, 10.0f), Vector3d(3.0f, 3.0f, 3.0f), boxShader));
auto boxShader1 = std::make_shared<RefractionShader>(1.05f, 1, Color(0,1,1), 0.7f);
scene.add(std::make_shared<Box>(Vector3d(9.0f, 3.0f, 12.0f), Vector3d(3.0f, 3.0f, 3.0f), boxShader1));
// auto boxShader = std::make_shared<RefractionShader>(1.05f, 1, Color(1,1,0), 0.7f);
// scene.add(std::make_shared<Box>(Vector3d(5.0f, 3.0f, 10.0f), Vector3d(3.0f, 3.0f, 3.0f), boxShader));
// auto boxShader1 = std::make_shared<RefractionShader>(1.05f, 1, Color(0,1,1), 0.7f);
// scene.add(std::make_shared<Box>(Vector3d(9.0f, 3.0f, 12.0f), Vector3d(3.0f, 3.0f, 3.0f), boxShader1));
// Add floor
auto floorShader = std::make_shared<SimpleShadowShader>(Color(0.9f, 0.9f, 0.9f));

38
shader/cloudshader.cpp
View file

@ -33,10 +33,10 @@ Color CloudShader::shade(const Scene &scene, const Ray &ray) const
// Calculate step length
int noiseSamples = settings.densitySamples;
float stepLength = cloudLength / noiseSamples;
float stepLength = cloudLength / (float) noiseSamples;
// Step through cloud
float transmittance = 1;
float accumulatedDensity = 0.0f;
Color cloudColor = Color(0, 0, 0);
for (int i = 0; i < noiseSamples; ++i)
{
@ -49,14 +49,14 @@ Color CloudShader::shade(const Scene &scene, const Ray &ray) const
if (sampleDensity > 0)
{
cloudColor += lightMarch(scene, samplePoint, lengthDirection) * stepLength * sampleDensity;
cloudColor += lightMarch(scene, samplePoint, lengthDirection, ray.primitive) * sampleDensity;
}
transmittance *= exp(-sampleDensity * stepLength * settings.lightAbsorptionThroughCloud);
if (transmittance < TRANSMITTANCE_BREAK) break; // Cloud is effectively opaque
accumulatedDensity += sampleDensity;
}
float transmittance = exp(-accumulatedDensity * settings.lightAbsorptionThroughCloud);
return background * transmittance + cloudColor;
}
@ -84,15 +84,17 @@ float CloudShader::getCloudDensity(Vector3d point) const
return density;
}
Color CloudShader::lightMarch(const Scene &scene, Vector3d currentInCloudPosition, Vector3d lengthDistance) const
Color CloudShader::lightMarch(const Scene &scene, Vector3d currentInCloudPosition, Vector3d lengthDistance,
const Primitive *cloudObject) const
{
Color cloudColor;
Color cloudColor = Color(0, 0, 0);
// For alle lights
for (const auto &light: scene.lights())
{
Ray ray = Ray(currentInCloudPosition - lengthDistance, normalized(lengthDistance));
ray.length = length(lengthDistance);
ray.primitive = cloudObject;
auto illumination = light->illuminate(scene, ray);
// Handle ambient lights
@ -106,22 +108,30 @@ Color CloudShader::lightMarch(const Scene &scene, Vector3d currentInCloudPositio
Ray lightRay;
lightRay.origin = currentInCloudPosition;
lightRay.direction = illumination.direction;
lightRay.primitive = cloudObject;
lightRay.length = 0; // Starting in cloud itself
float density = this->rayDensity(lightRay, illumination.distance);
density *= settings.lightAbsorptionTowardsLight;
// Proper light calculation
float transmittance = exp(-density) * (1 - exp(-density * 2));
float transmittance = getDensityTransmittance(density);
float scatter = scatterFactor(normalized(lengthDistance), illumination.direction);
float factor = settings.darknessThreshold + (scatter * transmittance) * (1 - settings.darknessThreshold); // (transmittance * scatter)
// TODO: Back to default
float factor = settings.darknessThreshold +
(1.0f - settings.darknessThreshold) * (1); // (transmittance * scatter)
cloudColor += factor * illumination.color;
}
return cloudColor;
}
float CloudShader::getDensityTransmittance(float density) const
{
return exp(-density) * (1 - exp(-density * 2)) / 0.4f;
}
Color CloudShader::transparency(const Scene &scene, const Ray &ray, float maxLength) const
{
float density = rayDensity(ray, maxLength);
@ -163,9 +173,7 @@ float CloudShader::rayDensity(const Ray &ray, float maxLength) const
Vector3d samplePoint = startPoint + i * stepLength * ray.direction;
// Get data at point
float sampleDensity = getCloudDensity(samplePoint) * stepLength;
density += sampleDensity * stepLength;
density += getCloudDensity(samplePoint) * stepLength;
}
// If there is length left, check if it is in the cloud recursively
@ -189,14 +197,14 @@ float CloudShader::rayDensity(const Ray &ray, float maxLength) const
float CloudShader::scatterFactor(Vector3d visualRay, Vector3d illuminationRay) const
{
// The asymmetry parameter
float g = 0.7f;
float g = settings.scatterWeight;
// The angle between the visual and illumination rays
float cosTheta = dotProduct(visualRay, illuminationRay);
// The Dual-Lob Henyey-Greenstein function
float blend = .5;
float scatter = HenyeyGreenstein(cosTheta,g) * (1-blend) + HenyeyGreenstein(cosTheta,-g) * blend;
float scatter = HenyeyGreenstein(cosTheta, g) * (1 - blend) + HenyeyGreenstein(cosTheta, -g) * blend;
// Clamp the result to the range [0, 1]
scatter = std::max(std::min(scatter, 1.0f), 0.0f);

15
shader/cloudshader.h
View file

@ -16,12 +16,13 @@ struct CloudSettings
int lightSamples = 100;
float scale = 10;
float densityOffset = -0.57f;
float densityIntensity = 7.0f;
float darknessThreshold = 0.07f;
float shadowIntensity = 0.8f;
float densityIntensity = 7.0f; // 7.0f
float darknessThreshold = 0.2f; // 0.07f
float shadowIntensity = 0.6f;
float shadowLightAbsorption = 1;
float lightAbsorptionTowardsLight = 0.94f;
float lightAbsorptionThroughCloud = 0.85f;
float lightAbsorptionTowardsLight = 1.0f;
float lightAbsorptionThroughCloud = 0.5f;
float scatterWeight = 0.5f;
};
class CloudShader : public Shader
@ -43,13 +44,15 @@ private:
float getCloudDensity(Vector3d point) const;
Color lightMarch(const Scene &scene, Vector3d currentInCloudPosition, Vector3d lengthDistance) const;
Color lightMarch(const Scene &scene, Vector3d currentInCloudPosition, Vector3d lengthDistance, const Primitive *cloudObject) const;
float rayDensity(const Ray &ray, float maxLength) const;
float scatterFactor(Vector3d visualRay, Vector3d illuminationRay) const;
float HenyeyGreenstein(float cosTheta, float g) const;
float getDensityTransmittance(float density) const;
};