I am not absolutely sure how to phrase this question, but what exactly makes for a good fit projection of a low poly mesh onto a high poly mesh for the purposes of generating a normal map?
Obviously, being close to the high detailed mesh is important, but there has to be more to it than that. I know how to manually tweak a mesh to get it more or less just so, but this is one of the most painful and annoyingly time consuming tasks imaginable when it comes to character modeling. Aside from eyeballing it, there must be some better way to define a good fit.
First, is it worse if there are protruding areas or idents as compared to the original? It seems visually getting the outline to be similar as possible is the key when doing it manually, but there must be some better definition. Hopefully one useful for tweaking parts of a mesh quickly so that I can save a lot of time with modeling.
I suppose you can define it as minimizing the area difference between the meshes, but this is painful to calculate when the high poly mesh has very many polies.
Anyway, I know this is a little vague, but I am hoping someone will have contemplated the same thing enough to fill in the missing pieces for me a little bit.
PS don't worry about warnings of this being hard to do, I already have similar helper tools I just want to tweak them to go beyond what they do at the moment.