I was thinking about adding some squash to a face rig project im working on in Maya, so i decided to do a quick test to see one approach of adding squashing to a region of mesh (like upperhead, lower head).
made two copies of sphere
for first sphere put the squash deformer on
selected verts of region want then make squash deformer
now plug first sphere into second as blendshape
in blendweight editor use replace/smooth tools to flood weights to get a smooth falloff.
Now could potentially build editable blendshapes from these starting results.
(for the control part i used a locator translate y and plugged it into factor of squash deformer)
Hope this is helpful,
Cheers,
Nate
Here's a helpful MEL script i wrote to put -1, 1 limit on translate y of selected objects, could tweak for other channels etc.
//make limits of y between -1 and 1 for($arg in `ls -sl`){ transformLimits -ty -1 1 -ety 1 0 $arg; transformLimits -ty -1 1 -ety 1 1 $arg; };
Inspired by,
Jason Schleifer (jasonschleifer dot com) (i first learned about squash deformer and doing rigging toolkit tests from reading his Animator Friendly Rigging course)