I imported an stl model of a mandible into 3D studio. I will later deformed it using FFD. I need to track the position (x, y, z coordinates) of a group of specific vertices--that I have selected as landmarks--before and after the FFD. I tried several methods, all without success. In one approach, I select each specific vertex and save it as a selection set. However, when I deform the object with the FFD modifier, I loose the ability to select the vertices again. Can anybody please help.