Im currently writing a new modifier for Blender. I called it “Restore Volume Modifier” because that is exactly what it does. If you deform your mesh by a modifier you will usualy get a result that has different volume then the original mesh.
This is a usual behavior, but sometimes you want to keep the volume. For example muscles of a character, like in blenrig. So im writing this modifier, which still has his issues, but currently i have a working version for Blender 2.54.
The only option as of now is a vertex group with which you can define which parts can be adjusted and which not.
To much text that is hard to understand? Look at this video and you will see what i mean:
If you have any suggestions, questions, comments. Plz answer me.
I believe it’s pretty much the same thing, it keeps the total volumetric area of the mesh constant.
I could see uses outside of muscles like simulating the pushing of clay, putty, or other malleable materials. Currently it wouldn’t allow chunks of mesh to break off but maybe that can be done via the SPH work by Farsthary and another developer by the name of Stephan
@Steve S
Maintain Volume is a Constraint, that scales the object/bone along its axis. If you scale x, then y and z are also scaled in a way that volume keeps constant. (Nice for ball hopping, and such stuff).
This is a modifier that works on mesh basis. So you can define yourself which parts of the mesh can be used to to reconstruct the original volume. In my linked example, only one side of the muscle can grow or shrink (i wanted it so). So you can create cases which arent possible for the maintain volume, which always manipulates the whole mesh.