public override bool RayIntersection(Ray r, out float t, out Point3D normal)
{
t = 0;
normal = null;
Point3D k = r.start - position;
float b = Point3D.scalar(k, r.dir);
float c = Point3D.scalar(k, k) - rad * rad;
float d = b * b - c;
if (d >= 0)
{
float sqrtfd = (float)Math.Sqrt(d);
float t1 = -b + sqrtfd;
float t2 = -b - sqrtfd;
float min_t = Math.Min(t1, t2);
float max_t = Math.Max(t1, t2);
t = (min_t > Ray.EPSILON) ? min_t : max_t;
if (t > Ray.EPSILON)
{
normal = Point3D.norm(r.tpos(t) - position);
return(true);
}
}
return(false);
}
Point3D RayTrace(Ray r, int rec, float env = 1, float impact = 1)
{
bool BackToAir = false;
Point3D clr = new Point3D(0, 0, 0);
if (rec <= 0 || impact < EPS)
{
return(clr);
}
Hit h = GenerateHit(r);
if (!h.succes)
{
return(clr);
}
if (Point3D.scalar(r.dir, h.normal) > 0)
{
h.normal = h.normal * -1;
BackToAir = true;
}
Point3D hit_pos = r.tpos(h.hit_point);
foreach (var l in lights)
{
clr += Point3D.blend(h.mat.clr, l.amb * h.mat.amb_coef);
if (IsVisibleLight(l.points[0], hit_pos))
{
clr += h.Shade(l, hit_pos, f);
}
}
if (h.mat.reflection_coef > 0)
{
Ray reflRay = h.Reflect(hit_pos);
clr += h.mat.reflection_coef * RayTrace(reflRay, rec - 1, env, impact * h.mat.reflection_coef);
}
if (h.mat.refraction_coef > 0)
{
Ray refrRay = h.Refract(hit_pos, BackToAir ? env / 1 : env / h.mat.env_coef);
if (refrRay != null)
{
clr += h.mat.refraction_coef * RayTrace(refrRay, rec - 1, impact * h.mat.reflection_coef);
}
}
return(clr);
}