public bool Scatter(Ray rayIn, ref HitRecord rec, out color attenuation, out Ray scattered)
{
attenuation = new color(1.0, 1.0, 1.0);
double etai_over_etat = rec.isFrontFace ? 1.0 / ref_idx : ref_idx;
var unit_direction = rayIn.Direction.unit_vector();
var cos_theta = Math.Min(Vec3.dot(-unit_direction, rec.normal), 1.0);
var sin_theta = Math.Sqrt(1 - cos_theta * cos_theta);
if (etai_over_etat * sin_theta > 1)
{
var reflected = RayTracer.Reflect(unit_direction, rec.normal);
scattered = new Ray(rec.p, reflected);
return(true);
}
var reflect_prob = schlick(cos_theta, etai_over_etat);
if (RayTracer.RandomDouble() < reflect_prob)
{
var reflected = RayTracer.Reflect(unit_direction, rec.normal);
scattered = new Ray(rec.p, reflected);
return(true);
}
var refracted = RayTracer.Refract(unit_direction, rec.normal, etai_over_etat);
scattered = new Ray(rec.p, refracted);
return(true);
}
public bool Scatter(Ray rayIn, ref HitRecord rec, out color attenuation, out Ray scattered)
{
Vec3 reflect = RayTracer.Reflect(rayIn.Direction.unit_vector(), rec.normal);
scattered = new Ray(rec.p, reflect + roughness * RayTracer.RandomInUnitSphere());
attenuation = albedo;
return(Vec3.dot(scattered.Direction, rec.normal) > 0);
}