public override bool Scatter(Ray r, HitRecord hitRecord, out Vector3 attenuation, out Ray scattered)
{
Vector3 reflected = VectorHelpers.Reflect(r.Direction.GetUnitVector(), hitRecord.SurfaceNormal);
scattered = new Ray(hitRecord.HitPoint, reflected + Fuzz * VectorHelpers.GetRandomInUnitSphere());
attenuation = Albedo;
return(Vector3.Dot(scattered.Direction, hitRecord.SurfaceNormal) > 0);
}
public override bool Scatter(Ray r, HitRecord hitRecord, out Vector3 attenuation, out Ray scattered)
{
attenuation = Vector3.One;
Vector3 reflected = VectorHelpers.Reflect(r.Direction, hitRecord.SurfaceNormal);
Vector3 outwardNormal;
float niOverNt;
float cosine;
if (Vector3.Dot(r.Direction, hitRecord.SurfaceNormal) > 0)
{
outwardNormal = -hitRecord.SurfaceNormal;
niOverNt = RefractiveIndex;
cosine = RefractiveIndex * Vector3.Dot(r.Direction, hitRecord.SurfaceNormal) / r.Direction.Length();
}
else
{
outwardNormal = hitRecord.SurfaceNormal;
niOverNt = 1.0f / RefractiveIndex;
cosine = -Vector3.Dot(r.Direction, hitRecord.SurfaceNormal) / r.Direction.Length();
}
float reflectProb = 1.0f;
if (Refract(r.Direction, outwardNormal.GetUnitVector(), niOverNt, out Vector3 refracted))
{
reflectProb = Schlick(cosine);
}
if (VectorHelpers.RandomFloat() < reflectProb)
{
scattered = new Ray(hitRecord.HitPoint, reflected);
}
else
{
scattered = new Ray(hitRecord.HitPoint, refracted);
}
return(true);
}
