Well, it would certainly take someone with a better head for numbers than me to say the least. Don't know about the xy to xyz. In UVMapper, you're working with a 2D surface that's been generated from the 3D data. If you move the extreme leftmost vertex of the lip material on one figure, to match the extreme leftmost lip vertex on the other figure, you're not messing with the z position directly, it was laready determined by the original mapping. The process ins't entirely arbitrary, you're taking 'lips ' from one xy place and moving them on the xy of 'lips' on another. If they're too big or too small, you adjust them to fit in the available space. That's the part I think should be possible for algorithms to be written to automate the process. Of course, it would be a "dumb" process in that it would only work with matching or equivalent materials on both figures. Also it wouldn't be able to see that some thing looked too stretched or squashed etc. That's wherethe judgement of a skilled human is definitely required. At any rate, programmers always like being the one to say, "That should be easy for you to implement, right?" instead of being on the receiving end and thinking, "This idiot has no idea what he's talking about."

"Democracy is a pathetic belief in the collective wisdom of individual ignorance." - H. L. Mencken