So I have two 3D scans of a retaining wall (one from 2013 and another from 2014) and I need to compare the two and see if it has moved. I am wondering if anyone in the world knows how to do so. Since the surfaces are vertical, and not horizontal, this has become a real 'head-scratcher' for me. I've tried to use the 'X' values as elevations, but since the retaining wall is not due east-west in the 'real-world' it isn't along the 'X' and 'Y' in AutoCAD, therefore when I tried to compare the surfaces, I get a gradual increased elevation difference from South-North due to the rotation from North (in the real-world) and the coordinates produced... SOMEONE PLEASE HELP, I CAN PAY!