I have a not-quite-developable surface, and I want to squash it flat to make a fabric pattern.  I thought the way to do this would be to use a strong CoPlanar constraint to make it flat, and springs on each mesh edge to pull them close to their correct lengths.

When I try this, it doesn't seem to do anything; the output of the solver is a null point for each of the vertices in the original mesh (screenshot attached).

I notice that the output of the CoPlanar component is a single Goal object, while the Length component gives me a list of separate Goals for each edge; is it something to do with that?  I am guessing this is something to do with my lack of Kangaroo experience...