public override Isect intersect(Ray ry)
{
double b, disc, t;
Isect ip;
v.sub2(c, ry.P);
b = Vec.dot(v, ry.D);
disc = b * b - Vec.dot(v, v) + r2;
if (disc < 0.0)
{
return null;
}
disc = Math.Sqrt(disc);
t = (b - disc < 1e-6) ? b + disc : b - disc;
if (t < 1e-6)
{
return null;
}
ip = new Isect();
ip.t = t;
ip.enter = Vec.dot(v, v) > r2 + 1e-6 ? 1 : 0;
ip.prim = this;
ip.surf = surf;
return ip;
}
/**
* Returns the shaded color
* @return The color in Vec form (rgb)
*/
Vec shade(int level, double weight, Vec P, Vec N, Vec I, Isect hit)
{
double n1, n2, eta, c1, cs2;
Vec r;
Vec tcol;
Vec R;
double t, diff, spec;
Surface surf;
Vec col;
int l;
col = new Vec();
surf = hit.surf;
R = new Vec();
if (surf.shine > 1e-6)
{
R = SpecularDirection(I, N);
}
// Computes the effectof each light
for (l = 0; l < lights.Length; l++)
{
L.sub2(lights[l].pos, P);
if (Vec.dot(N, L) >= 0.0)
{
t = L.normalize();
tRay.P = P;
tRay.D = L;
// Checks if there is a shadow
if (Shadow(tRay, t) > 0)
{
diff = Vec.dot(N, L) * surf.kd *
lights[l].brightness;
col.adds(diff, surf.color);
if (surf.shine > 1e-6)
{
spec = Vec.dot(R, L);
if (spec > 1e-6)
{
spec = Math.Pow(spec, surf.shine);
col.x += spec;
col.y += spec;
col.z += spec;
}
}
}
} // if
} // for
tRay.P = P;
if (surf.ks * weight > 1e-3)
{
tRay.D = SpecularDirection(I, N);
tcol = trace(level + 1, surf.ks * weight, tRay);
col.adds(surf.ks, tcol);
}
if (surf.kt * weight > 1e-3)
{
if (hit.enter > 0)
tRay.D = TransDir(null, surf, I, N);
else
tRay.D = TransDir(surf, null, I, N);
tcol = trace(level + 1, surf.kt * weight, tRay);
col.adds(surf.kt, tcol);
}
// garbaging...
tcol = null;
surf = null;
return col;
}