The many functions in this class are not listed here. The most common use of this is to maintain a transformation matrix for transforming 3D vectors from one coordinate space to another, i.e. to rotate, translate, and scale them. Once a 4 by 4 matrix `M' has been set up, then a vector `V' is tranformed and placed in the view vector `VT' as: M.multpoint3d(V, VT)