private Color TraceRay(Ray r, int depth)
{
if (depth > MAX_DEPTH)
{
return(Color.Black);
}
IntersectionInfo info = GetFirstIntersection(r);
if (info == null) //луч не пересекает предмет
{
return(scene.InfinityColor);
}
double R = 0, G = 0, B = 0;
//луч пересекает предмет
double IdR = 0, IdG = 0, IdB = 0;
double IsR = 0, IsG = 0, IsB = 0;
double pFong = info.Material.FongCoeff; //
IEnumerator <Light> lights = scene.Lights;
lights.Reset();
while (lights.MoveNext())
{
Light L = lights.Current;
Vector3D V = new Vector3D(info.CrossPoint, L.Position); //направление на источник L
V *= (1 / V.Length);
if (IsVisible(L, info.CrossPoint))
{
double distance = VectorOperations.Distance(L.Position, info.CrossPoint);
double attenuation = 1; // L.Attenuation(distance);
if (info.Material.Diffusion > 0) //для предмета задано свойство диффузного отражения
{
double cos = VectorOperations.Cos(info.Normal, V);
if (cos < 0)
{
cos = 0;
}
IdR += L.Color.R * cos / attenuation;
IdG += L.Color.G * cos / attenuation;
IdB += L.Color.B * cos / attenuation;
}
if (info.Material.Specularity > 0) //для предмета задано свойство зеркального отражения
{
Vector3D reflected;
if (VectorOperations.ReflectedVector(info.Normal, r.Direction, out reflected))
{
double cos = VectorOperations.Cos(V, reflected);
if (cos < 0)
{
cos = 0;
}
IsR += L.Color.R * Math.Pow(cos, pFong) / attenuation;
IsG += L.Color.G * Math.Pow(cos, pFong) / attenuation;
IsB += L.Color.B * Math.Pow(cos, pFong) / attenuation;
}
}
}
}
R += info.Material.Diffusion * IdR * info.Material.Color.R / 255;
G += info.Material.Diffusion * IdG * info.Material.Color.G / 255;
B += info.Material.Diffusion * IdB * info.Material.Color.B / 255;
R += info.Material.Specularity * IsR;
G += info.Material.Specularity * IsG;
B += info.Material.Specularity * IsB;
if (info.Material.Reflection > 0)
{
Vector3D reflected;
if (VectorOperations.ReflectedVector(info.Normal, r.Direction, out reflected))
{
Ray reflectedRay = new Ray(info.CrossPoint, reflected);
Color reflectedColor = TraceRay(reflectedRay, depth + 1);
R += info.Material.Reflection * reflectedColor.R;
G += info.Material.Reflection * reflectedColor.G;
B += info.Material.Reflection * reflectedColor.B;
}
}
if (info.Material.Transparency > 0)
{
double n12 = info.Material.RefractiveIndex;
Vector3D refracted;
if (VectorOperations.RefractedVector(info.Normal, r.Direction, n12, out refracted))
{
Ray refractedRay = new Ray(info.CrossPoint, refracted);
Color refractedColor = TraceRay(refractedRay, depth + 1);
R += info.Material.Transparency * refractedColor.R;
G += info.Material.Transparency * refractedColor.G;
B += info.Material.Transparency * refractedColor.B;
}
}
R += info.Material.Color.R * scene.Ambient;
G += info.Material.Color.G * scene.Ambient;
B += info.Material.Color.B * scene.Ambient;
return(Color.FromArgb(Math.Min((int)R, 255), Math.Min((int)G, 255), Math.Min((int)B, 255)));
}