This tutorial explains a pair of important user defined functions, the “Navigator_u()” and the “Navigator_v()”. These functions save the user nine columns of formulas by calculating the effects of: 3-dimensional shift, rotations around the three axes of coordinates and 3D-2D perspective mapping. These user defined functions are also easy to use compared to writing all the perspective mapping equations from… Read More... "Instant 3D-2D Perspective Mapping – the Navigator Functions – a convenient pair of user defined functions"