public override double3 CalculateColor(Scene scene, Traceable traceable,
IntersectData data, Ray ray, TraceData traceData)
{
double3 resultColor = double3.Zero;
double3 n = traceable.GetNormal(data);
foreach (SpotLight light in scene.Lights)
{
double3 l = light.Pos - data.P;
double distance = l.Length;
l = l.Normalized;
double nDotL = n & l;
if (nDotL <= 0)
{
continue;
}
double shadowEdgeAttenuation = 1;
List <IntersectData> shadowIsecs = scene.Intersect(new Ray(traceable.Advance(data.P, l), l));
if (shadowIsecs.Count > 0)
{
IntersectData obstacleIsecData = shadowIsecs.OrderBy(shadowIsecData => (shadowIsecData.P - data.P).Length).First();
if ((obstacleIsecData.P - data.P).Length < distance)
{
double3 obstacleL = light.Pos - obstacleIsecData.P;
obstacleL = obstacleL.Normalized;
double3 obstacleN = obstacleIsecData.Object.GetNormal(obstacleIsecData);
double3 obstacleR = l.ReflectI(obstacleN);
shadowEdgeAttenuation = obstacleR & obstacleL;
if (shadowEdgeAttenuation <= 0)
{
continue;
}
shadowEdgeAttenuation = Math.Pow(shadowEdgeAttenuation, 3);
}
}
double3 diffuse = BaseColor ^ light.DiffuseColor * nDotL;
double3 r = l.Reflect(n, nDotL);
double rDotV = Math.Max(0, (-ray.l) & r);
double3 specular = Math.Pow(rDotV, SpecularPower) * light.SpecularColor;
double attenuation = Math.Log(distance + light.AttenuationBase, light.AttenuationBase);
resultColor += (diffuse + specular) * shadowEdgeAttenuation / attenuation;
}
if (traceData.Reflections > 0)
{
double3 r = ray.l.ReflectI(n);
double3 p = traceable.Advance(data.P, r);
double3 reflectionColor = scene.Trace(new Ray(p, r), traceData.GetReflected());
resultColor += reflectionColor * ReflectionAttenuation;
}
else
{
TraceData.ReflectionLimitExceedCount++;
return(TraceData.ReflectionLimitExceedColor);
}
return(resultColor + scene.AmbientColor);
}
