Hi, I have CAD/DFX/STL file containing a model with some pits in it in various positions. For each of these pits, I would like to create a local plane around the pit, making the surface of the model my x = 0 and make the program find the deepest point of the pit. What free program can do this. I know the feature is included in Polyworks professional, but only need this function, and therefor don't want to buy the whole program./Anders