OEGeom3DCrossProd
template<class T>
void OEGeom3DCrossProd(T* x, const T* p, const T* q, const T* r)
template<class T, class U, class V>
void OEGeom3DCrossProd(T* x, const U* p, const V* q)
Calculates the cross product of the two three element vectors p and
q. The first form computes \(x = (p-q)*(r-q)\) and
the second form computes \(x = p * q\).