public Vector4 ShadeHit(Computations comp, int remainingReflections = 0)
{
var surfaceColor = Lights.Select(light =>
comp.Object.Material.ComputeColor(
light,
comp.Object,
comp.OverPoint,
comp.EyeV,
comp.NormalV,
inShadow: IsShadowed(light, comp.FarOverPoint)))
.Aggregate(VColor.Black, (finalColor, color) => finalColor + color);
var reflectedColor = ComputeReflectedColor(comp, remainingReflections);
var refractedColor = ComputeRefractedColor(comp, remainingReflections);
var material = comp.Object.Material;
if (material.Reflective > 0 && material.Transparency > 0)
{
var reflectance = comp.GetSchlickReflectance();
return(surfaceColor + reflectedColor * reflectance + refractedColor * (1 - reflectance));
}
else
{
return(surfaceColor + reflectedColor + refractedColor);
}
}
public Vector4 ComputeReflectedColor(Computations comps, int remainingReflections = 0)
{
if (comps.Object.Material.Reflective.IsZero() || remainingReflections == 0)
{
return(VColor.Black);
}
var reflectRay = CreateRay(comps.OverPoint, comps.ReflectV);
var color = ComputeColor(reflectRay, remainingReflections - 1);
return(color * comps.Object.Material.Reflective);
}
public Vector4 ComputeColor(Ray ray, int remainingReflections = 0)
{
var xs = Intersect(ray);
var hit = xs.TryGetHit();
if (hit == null)
{
return(VColor.Black);
}
var comp = Computations.Prepare(hit, ray, xs);
return(ShadeHit(comp, remainingReflections));
}
public Vector4 ComputeRefractedColor(Computations comps, int remainingReflections)
{
if (comps.Object.Material.Transparency.IsZero() || remainingReflections == 0)
{
return(VColor.Black);
}
var nRatio = comps.N1 / comps.N2;
var cosI = Dot(comps.EyeV, comps.NormalV);
var sinT2 = nRatio * nRatio * (1 - cosI * cosI);
if (sinT2 > 1)
{
return(VColor.Black);
}
var cosT = Sqrt(1 - sinT2);
var direction = comps.NormalV * (nRatio * cosI - cosT) - comps.EyeV * nRatio;
var refractRay = new Ray(comps.UnderPoint, direction);
return(ComputeColor(refractRay, remainingReflections - 1) * comps.Object.Material.Transparency);
}
