private Vector3 CalcReflection(HitPoint hp, Vector3 OP, RenderSettings settings, int depth, float reflectionDecay)
{
if (!hp.IsHit())
{
return(_baseColor);
}
if (depth >= REFLECTION_LIMIT)
{
return(Vector3.Zero);
}
if (_spheres[hp.SphereIndex].ReflectionFactor <= 0.0f)
{
return(Vector3.Zero);
}
var position = hp.Position;
var n = Vector3.Normalize(position - _spheres[hp.SphereIndex].Center);
var r = Vector3.Reflect(hp.Direction, n);
var H = position + n * 0.01f;
var hp2 = _spheres.GetHitPoint(r, H);
if (!hp2.IsHit())
{
return(_baseColor);
}
return(_spheres[hp.SphereIndex].ReflectionFactor * reflectionDecay * CalcColor(hp2, settings) +
CalcReflection(hp2, H, settings, depth + 1, reflectionDecay * reflectionDecay));
}
private Vector3 CalcColor(HitPoint hp, RenderSettings settings)
{
if (!hp.IsHit())
{
return(_baseColor);
}
var sphere = _spheres[hp.SphereIndex];
var position = hp.Position;
var n = Vector3.Normalize(position - sphere.Center);
var colorDiffuse = Vector3.Zero;
var colorSpecular = Vector3.Zero;
foreach (var light in _lights)
{
var l = Vector3.Normalize(light.Position - position);
var r = 2 * Vector3.Dot(l, n) * n - l;
var cosTheta = Vector3.Dot(n, l);
if (cosTheta >= 0)
{
// Diffuse lighting
if (settings.Diffuse)
{
Vector3 diff = light.Color * cosTheta * sphere.GetColor(n);
if (settings.Shadow)
{
diff *= CalcShadowFactor(position + n * 0.01f, light);
}
colorDiffuse += diff;
}
// Specular lighting
if (settings.Specular)
{
var alpha = Vector3.Dot(r, Vector3.Normalize(position - hp.Origin));
if (alpha < 0)
{
colorSpecular += light.Color * (float)Math.Abs(Math.Pow(alpha, K));
}
}
}
}
return(sphere.Emission + colorDiffuse + colorSpecular);
}