Sometimes LEGO bricks don't fall into the regular 0.8/1.6mm rule. This will explain how to get "lumpy" 3D surface data from LDraw DAT files and use them to create your own intelligent parts. *I use the AutoDesk Inventor Pro suite, which includes Inventor Pro and 3D Studio Max. I will discuss using certain file formats, but you need to determine what your software will import/export. *I've been told that IV 2017+ will let you measure the LDraw data directly in Inventor, removing the whole 3DMax conversions steps.