I'm written a script to merge 3d point coordinates from 3d faces to basically generate an average face.

say I have 10 faces, I just add each vertex and then divide by 10, for each point.

The resulting face is an average of these.

But I only get one "perfectly" average face.

How can I adjust this algorithm to generate a large number of different proportions of each face, for example weighting the amount a particular face contributes to the end result?