public override Intersection intersect(Ray ray)
{
var eo = Vector.Add(center, -ray.start);
var v = Vector.DotProduct(eo, ray.dir);
var dist = 0.0f;
if (v >= 0)
{
var disc = radius2 - (Vector.DotProduct(eo, eo) - v * v);
if (disc >= 0)
{
dist = (float)(v - Math.Sqrt(disc));
}
}
if (Math.Abs(dist) < 1e-5)
{
return(null);
}
return(new Intersection {
thing = this, ray = ray, dist = dist
});
}
public override Vector normal(Vector pos)
{
return(Help.norm(Vector.Add(pos, -center)));
}
