public bool Intersect(Ray ray, ref Hit hit, float tmin = 0f, float tmax = float.MaxValue)
{
Vector3 oc = ray._origin - _center;
float b = Vector3.Dot(oc, ray._direction);
float c = Vector3.Dot(oc, oc) - _radius * _radius;
float discriminant = b * b - c;
if (discriminant > 0f)
{
float sqrD = (float)Math.Sqrt(discriminant);
float t = (-b - sqrD);
if (t < tmax && t > tmin)
{
hit._point = ray.eval(t);
hit._normal = (hit._point - _center);
hit._normal.Normalize();
hit._t = t;
return(true);
}
t = (-b + sqrD);
if (t < tmax && t > tmin)
{
hit._point = ray.eval(t);
hit._t = t;
return(true);
}
return(true);
}
return(false);
}