func (v Vec3) Cross(v1 Vec3) Vec3 {
	return Vec3{
		v[1]*v1[2] - v[2]*v1[1],
		v[2]*v1[0] - v[0]*v1[2],
		v[0]*v1[1] - v[1]*v1[0],
	}
}
func (v Vec3) Cross(v1 Vec3) Vec3 {
	return Vec3{
		v[1]*v1[2] - v[2]*v1[1],
		v[2]*v1[0] - v[0]*v1[2],
		v[0]*v1[1] - v[1]*v1[0],
	}
}
func ( v Vec3 ) Cross ( v1 Vec3 ) Vec3 { return Vec3 { v [ 1 ] * v1 [ 2 ] - v [ 2 ] * v1 [ 1 ] , v [ 2 ] * v1 [ 0 ] - v [ 0 ] * v1 [ 2 ] , v [ 0 ] * v1 [ 1 ] - v [ 1 ] * v1 [ 0 ] , } }
// Cross returns the cross product of two vectors. v x v1
Cross returns the cross product of two vectors . v x v1