public bool Scatter(Ray rIn, HitRecord record, Vector3 attenuation, Ray scattered, Random rand)
{
Vector3 reflected = Vector3.Reflect(rIn.Direction.Normalize(), record.Normal);
// Save scattered & attenuation values
scattered.Set(new Ray(record.Point, reflected + Fuzz * Vector3.RandomInUnitSphere(rand)));
attenuation.Set(Albedo);
return(scattered.Direction.Dot(record.Normal) > 0);
}
public bool Scatter(Ray rIn, HitRecord record, Vector3 attenuation, Ray scattered, Random rand)
{
Vector3 scatterDirection = record.Normal + Vector3.RandomUnitVector(rand);
// Catch degenerate scatter direction
if (scatterDirection.NearZero())
{
scatterDirection = record.Normal;
}
scattered.Set(new Ray(record.Point, scatterDirection));
attenuation.Set(Albedo);
return(true);
}
public bool Scatter(Ray rIn, HitRecord record, Vector3 attenuation, Ray scattered, Random rand)
{
attenuation.Set(new Vector3(1.0, 1.0, 1.0));
double refractionRatio = record.FrontFace ? (1.0 / RefractionIndex) : RefractionIndex;
Vector3 unitDirection = rIn.Direction.Normalize();
double cosTheta = Math.Min(record.Normal.Dot(-unitDirection), 1.0);
double sinTheta = Math.Sqrt(1.0 - cosTheta * cosTheta);
bool cannotRefract = refractionRatio * sinTheta > 1.0;
Vector3 direction;
if (cannotRefract || reflectance(cosTheta, refractionRatio) > rand.NextDouble())
{
direction = Vector3.Reflect(unitDirection, record.Normal);
}
else
{
direction = Vector3.Refract(unitDirection, record.Normal, refractionRatio);
}
scattered.Set(new Ray(record.Point, direction));
return(true);
}
