public static Vektor refract(Vektor uv, Vektor n, double etai_over_etat)
{
var cos_theta = Math.Min(Vektor.dot(uv * -1, n), 1);
Vektor r_out_perp = etai_over_etat * (uv + cos_theta * n);
Vektor r_out_parallel = -Math.Sqrt(Math.Abs(1 - r_out_perp.length_squared())) * n;
return(r_out_perp + r_out_parallel);
}
public static Vektor random_in_unit_disk()
{
while (true)
{
var p = new Vektor(Mathe.random_1Tom1(), Mathe.random_1Tom1(), 0);
if (p.length_squared() >= 1)
{
continue;
}
return(p);
}
}
public static double hit_sphere(Vektor center, double radius, ray r)
{
Vektor oc = r.Origin - center;
var a = r.Direction.length_squared();
var half_b = Vektor.dot(oc, r.Direction);
var c = oc.length_squared() - radius * radius;
var discriminant = half_b * half_b - a * c;
if (discriminant < 0)
{
return(-1);
}
else
{
return((-half_b - Math.Sqrt(discriminant)) / a);
}
}
public override zwischenSpeicher Hit(ray r, double t_min, double t_max, hit_record rec)
{
zwischenSpeicher zw = new zwischenSpeicher();
Vektor oc = r.Origin - center;
var a = r.Direction.length_squared();
var half_b = Vektor.dot(oc, r.Direction);
var c = oc.length_squared() - radius * radius;
var discriminant = half_b * half_b - a * c;
if (discriminant < 0)
{
zw.IsTrue = false;
return(zw);
}
var sqrtd = Math.Sqrt(discriminant);
var root = (-half_b - sqrtd) / a;
if (root < t_min || t_max < root)
{
root = (-half_b + sqrtd) / a;
if (root < t_min || t_max < root)
{
zw.IsTrue = false;
return(zw);
}
}
rec.t = root;
rec.p = r.at(rec.t);
Vektor outward_normal = (rec.p - center) / radius;
rec.set_face_normal(r, outward_normal);
rec.mat_ptr = mat_ptr;
zw.rec = rec;
zw.IsTrue = true;
return(zw);
}