public bool Scatter(Ray ray, HitRecord hitRecord, out ScatterRecord sRecord)
{
sRecord = new ScatterRecord();
var normal = hitRecord.normal;
var point = hitRecord.point;
var reflected = Exten.reflect(ray.direction, normal);
if (fuzz > 0)
{
ONB o = new ONB(reflected);
var next = RandomCosineDir();
reflected = o.Local(next);
}
sRecord.attenuation = color;
sRecord.pdf = new ConstPDF(reflected);
return glm.dot(ray.direction, normal) < 0;
}
public bool Scatter(Ray ray, HitRecord hitRecord, out ScatterRecord sRecord)
{
sRecord = new ScatterRecord();
var normal = hitRecord.normal;
var point = hitRecord.point;
sRecord.attenuation = new vec3(1.0f, 1.0f, 1.0f);
float eta = ref_idx;
var n = normal;
if (glm.dot(ray.direction, normal) > 0)//从内到外
{
n = new vec3(-normal.x, -normal.y, -normal.z);
}
else
{
eta = 1.0f / eta;
}
vec3 r;
float prob = 1.0f;
if (Exten.refract(ray.direction, n, eta, out r))
{
float cosi = -glm.dot(ray.direction, n);
float cost = -glm.dot(r, n);
prob = fresnel(cosi, cost, eta);
}
if (Exten.rand01() < prob)
{
vec3 reflected = Exten.reflect(ray.direction, normal);
sRecord.pdf = new ConstPDF(reflected);
}
else
{
sRecord.pdf = new ConstPDF(r);
}
return true;
}