A set of routines to produce grids with multiple layers of subdivision. Line thickness and color can be specified for each level of subdivision. The grid size can be specified in any desired units. The three grids are Cartesian (rectangular), Triangular (the angle is adjustable), and Perspective (2-point perspective with adjustable perspective points). Note that 0.91 and 0.48 require different releases; if you want to use this extension with 0.48, please download it from the external link.