bool rayIntersects(RayN<N, T> const & ray, T max_time = -1) const
{
if (max_time >= 0)
return rayIntersectionTime(ray, max_time) >= 0;
VectorT co = ray.getOrigin() - center;
T c = co.squaredNorm() - radius * radius;
if (c <= 0) // origin is inside ball
return true;
T a = ray.getDirection().squaredNorm();
T b = 2 * co.dot(ray.getDirection());
// Solve quadratic a * t^2 + b * t + c = 0
T b2 = b * b;
T det = b2 - 4 * a * c;
if (det < 0) return false;
if (a > 0)
return b <= 0 || det >= b2;
else if (a < 0)
return b >= 0 || det >= b2;
else
return false;
}
RayIntersectionN<N, T> rayIntersection(RayN<N, T> const & ray, T max_time = -1) const
{
T t = rayIntersectionTime(ray, max_time);
if (t >= 0)
return RayIntersectionN<N, T>(t, &normal);
else
return RayIntersectionN<N, T>(-1);
}
RayIntersectionN<N, T> rayIntersection(RayN<N, T> const & ray, T max_time = -1) const
{
T t = rayIntersectionTime(ray, max_time);
if (t >= 0)
{
VectorT p = ray.getPoint(t);
VectorT n = p - center;
return RayIntersectionN<N, T>(t, &n);
}
else
return RayIntersectionN<N, T>(-1);
}
/**
* Get the intersection of a ray with the object, including the hit time and the normal at the intersection point. A
* negative time is returned if there was no intersection in the forward direction. If the normal cannot be computed, the
* zero vector is returned.
*
* @param ray The ray to test for intersection.
* @param max_time Maximum allowable hit time, ignored if negative.
*
* @note The returned normal need not have unit length.
*/
virtual RayIntersectionN<N, T> rayIntersection(RayN<N, T> const & ray, T max_time = -1) const
{ return RayIntersectionN<N, T>(rayIntersectionTime(ray, max_time)); }
/**
* Check if a ray intersects the object in the forward direction.
*
* @param ray The ray to test for intersection.
* @param max_time Maximum allowable hit time, ignored if negative.
*/
virtual bool rayIntersects(RayN<N, T> const & ray, T max_time = -1) const
{ return rayIntersectionTime(ray, max_time) >= 0; }
