operator*(const SGVec3<T>& v, S s)
{ return SGVec3<T>(s*v(0), s*v(1), s*v(2)); }
+/// multiplication as a multiplicator, that is assume that the first vector
+/// represents a 3x3 diagonal matrix with the diagonal elements in the vector.
+/// Then the result is the product of that matrix times the second vector.
+template<typename T>
+inline
+SGVec3<T>
+mult(const SGVec3<T>& v1, const SGVec3<T>& v2)
+{ return SGVec3<T>(v1(0)*v2(0), v1(1)*v2(1), v1(2)*v2(2)); }
+
/// component wise min
template<typename T>
inline