I am trying to write a WPF windows application that dynamically creates a 3 D object for an existing 3D Image. The senerio is as follows. Mark the points randomly on the existing 3D Image. Create a 3D object based on the points already marked. Check the below Sample Screenshots. Screenshot 1 and Screenshot 2 I am successfully able to load the 3D file to the WPF form. And was able to perform the rotation using TrackballDecorator 3D Tools library. I have just read this related post. however i didn't get it exactly :) So,can you suggest some efficient methods to achieve it.