public override bool Scatter(Scene scene, Ray ray, HitRecord rec, out Attenuation attenuation, out Ray scattered)
{
Vector3 outward_normal;
float ni_over_nt;
attenuation = Attenuation.Multiply(Vector3.One);
float reflect_prob;
float cosine;
if (Vector3.Dot(ray.direction, rec.normal) > 0)//内部射出
{
outward_normal = -rec.normal;
ni_over_nt = refIndex;
cosine = refIndex * Vector3.Dot(ray.direction, rec.normal) / ray.direction.Length();
}
else //外部射入
{
outward_normal = rec.normal;
ni_over_nt = 1.0f / refIndex;
//ni_over_nt = this.ri_out / this.ri_in;
cosine = -Vector3.Dot(ray.direction, rec.normal) / ray.direction.Length();
}
if (Refract(ref ray.direction, ref outward_normal, ni_over_nt, out Vector3 refracted))
{
reflect_prob = Schlick(cosine, refIndex);
}
public override bool Scatter(Scene scene, Ray ray, HitRecord hit, out Attenuation attenuation, out Ray scattered)
{
Vector3 target = hit.position + hit.normal + Sphere.RandomInUnitSphere();
scattered = new Ray(hit.position, target - hit.position);
attenuation = Attenuation.Multiply(albedo);
return(true);
}
public override bool Scatter(Scene scene, Ray ray, HitRecord hit, out Attenuation attenuation, out Ray scattered)
{
var direction = Vector3.Normalize(ray.direction);
Vector3 reflected = Vector3.Reflect(direction, hit.normal);
scattered = new Ray(hit.position, reflected + fuzz * Sphere.RandomInUnitSphere());
attenuation = Attenuation.Multiply(albedo);
//return true;
return(Vector3.Dot(scattered.direction, hit.normal) > 0);
}
