PDA

View Full Version : Painting weights w/ Maya Muscle


mmacmahon
02-18-2011, 06:47 AM
I'm adding muscles to a skeleton whose joints I've already weighted. When I paint sticky and sliding weights for the muscles, random vertices are frequently affected by my brush—ie, I'm painting weights on my model's hind leg, and some vertices on the jaw and neck are consistently affected. It's making weighting much more tedious since I have to go back and remove weighting on other areas of the model before moving on...

Is there a way to correct this or is it some bug? On a related note I haven't set up UV's for my model and wondered if this would contribute to the problem. However, I've only had this problem with painting muscle weights, and not joint weights.

Does anybody have any suggestions?

Thanks a bunch!

uiron
02-18-2011, 07:36 AM
this happens when you downscale weights, either by smoothing, scaling, or replacing with lower value. imagine such weights for vertex N:


L_legJoint: 1.0
NeckJoint: 0.0
R_fingerJoint: 0.0

now you're smoothing weights on L_legJoint, and as a result of this, weights on this influence has to be reduced to comply the smoothing pattern, so we have:

L_legJoint: 0.9
NeckJoint: 0.0
R_fingerJoint: 0.0

now, weights on one vertex have to be a sum of 1.0 (muscle system does not support post-normalize). so what happens is, you can't be sure where the remaining 0.1 of weight go, most probably it becomes:

L_legJoint: 0.9
NeckJoint: 0.05
R_fingerJoint: 0.05.

There's actually not a lot you can do to work around this. the only brushes that are mathematically guaranteed to not to mess with other weights are: "replace" of value 1.0;any "add" value.

mmacmahon
02-18-2011, 07:40 AM
Thanks Uiron!

Looking at the list in my Muscle Paint menu, all the joints are included as well (probably because I turned them into capsules)...is there a way to remove them from the menu? (The original joints are already weighted.) Otherwise, would flooding all the none-muscles in the Muscle Paint menu with zero cause problems?

Thanks for your help.

CGTalk Moderation
02-18-2011, 07:40 AM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.