public bool Scatter(ref Ray r, ref Hit_record rec, ref Vector3 attenuation, ref Ray scattered, System.Random seed)
{
Vector3 target = rec.normal.normalized * 0.5f +
new Vector3(Chapter12.RandomFloat11(seed), Chapter12.RandomFloat11(seed), Chapter12.RandomFloat11(seed)).normalized;
scattered.origin = rec.hitpoint;
scattered.direction = target;
attenuation = albedo;
return(true);
}
public bool Scatter(ref Ray r, ref Hit_record rec, ref Vector3 attenuation, ref Ray scattered, System.Random seed)
{
Vector3 outward_normal = Vector3.zero;
Vector3 reflected = Vector3.Reflect(r.direction.normalized, rec.normal.normalized);
float ni_over_nt = 0f;
attenuation.x = 1.0f;
attenuation.y = 1.0f;
attenuation.z = 1.0f;
Vector3 refracted;
float reflect_prob;
float cosine;
if (Vector3.Dot(r.direction, rec.normal) > 0)
{
outward_normal = -rec.normal;
ni_over_nt = ref_idx;
cosine = ref_idx * Vector3.Dot(r.direction, rec.normal) / r.direction.magnitude;
}
else
{
outward_normal = rec.normal;
ni_over_nt = 1.0f / ref_idx;
cosine = -Vector3.Dot(r.direction.normalized, rec.normal) / r.direction.magnitude;
}
var bRefracted = Refract(r.direction, outward_normal, ni_over_nt, out refracted);
if (bRefracted)
{
reflect_prob = Schlick(cosine, ref_idx);
}
else
{
scattered.origin = rec.hitpoint;
scattered.direction = reflected;
reflect_prob = 1.0f;
}
if (Chapter12.RandomFloat01(seed) < reflect_prob)
{
scattered.origin = rec.hitpoint;
scattered.direction = reflected;
}
else
{
scattered.origin = rec.hitpoint;
scattered.direction = refracted;
}
return(true);
}
private Vector3 Random_in_unit_sphere(System.Random seed)
{
return(new Vector3(Chapter12.RandomFloat11(seed), Chapter12.RandomFloat11(seed), Chapter12.RandomFloat11(seed)).normalized);
}
