I follow the forums here and have learned about the latest guides for "coupled" simulation (simulating muscles and fat tissues together). I'm sold...the results are pretty great comparatively--BUT...I've encountered an issue with the workflow that maybe someone on here can point me to the (or just better) solution:
The default pressure of the fat tissue destroys the rest volume of the muscles (in my case).
For the most part, I'm using the values of zMaterials on the muscles/ fat and pressure settings etc from the Mr. Ink example and a few various examples found here on the forums...so what I'm gathering are pretty standard settings (though I've relieved some of the inner fat tissue pressure--even by half--maybe I just need to go farther?!).
My current workaround/ hack/ fix is to do the simulation--then wrap deform the original rendermesh to the pressurized rest frame of the sim. For example, my animation starts at -20 with pressure/ gravity/ etc all off...ramps in for 5 frames, and then I let it settle for a few more. So I wrap deform the rendermesh to the simmed fat tissue at frame -10.
It works ok, but I'd like to find a better solution to keep some of the missing volumes during the sim. i.e. I'll call it a CBB (could be better).
If I sim the muscles and fat tissue separately (the "old" way) the muscle volume keeps it shape and is fine--but to be honest, there's something "missing" from this when comparing it to the coupled end result--the tissues just "feel" better/ more natural during the coupled solve (imo). And biggest difference I notice is in the "creases" of arm pits/ inner elbow/ knee bends the fat tissue doesn't stick the same and slides out more often then not--not giving those "nice creases" in the collisions I'm missing from the coupled solves. -- It slides out due to the muscles not having any gaps for the fat tissue to actually slide/ stick into.
I've seen another post about this here on the forums, but didn't see a result (yet). Anyone have some thoughts on maybe some "better" settings to make the muscles keep their rigidity a bit more for a coupled solve?
One thing I've done in the past, is "inflate" the muscles to fill all gaps with nCloth (worked pretty great on the early Mr. Ink anatomy transfer tests I did some time ago when first testing Ziva)--but it's pretty involved and I'm hoping not to have to change the actual muscles if I don't "need" to (yet)--and not sure it'll even solve this problem--it was more of a modelling/ transfer fix.
Here's an example of my typical results (until I delete it from my drive 😉
Always open to any thoughts/ input!
Rest (the images look subtle, but the video really shows a significant change):