Muscle Test

Here’s a vid of a muscle test. I used the Maintain Volume bone constraint to flex the muscle. Create a separate vertex group for each muscle. In Weight Painting mode, paint the area of the muscle to be deformed. When the bone is scaled, the muscle flexes. You can use IPO drivers to link the scaling of the muscle bone to the rotation of the leg bones.

T-rex model is by Cyberchinchilla and is available at Turbosquid. I had to rework the leg. Fortunately he provided a low-res version that was easy to edit.

Steve S

Nice job Steve!

In case you are interested in seeing another muscle approach, here is a post of my rig:

I used a technique based on shrinkwrap. It is closer to the muscle simulation you can see in other 3d packages. It also a lot more resources consuming than you bone based technique, that’s the negative side of it.

Here’s a video explaining how the rig works:

You can download the rig from here if you want:

It’s all Blender 2.49. I’m now working on a Blender 2.5 version of the rig.

Here’s the post of that WIP:

Hope to see more of your progress soon!!

Wow! That’s a fantastic system, Juan. It must have taken a lot of time and effort. I’ve seen muscle rigs for Max and Maya but didn’t realize someone had done one for Blender. I’ll have to play around with it and see how I can adapt it to T-rex.

Steve S


Actually the rig is much more than a muscle system, BlenRig is an auto-rigging system, but that’s off topic :stuck_out_tongue:

In order to make a shrinkwrap muscle system, you just have to create the muscles with simple shapes, and then add a subsurf modifier to those muscles, otherwise you’ll get a jumpy deformation. Then, it is just a matter of weight painting. I also used the smooth modifier to smooth out certain parts of the model after the shrinkwrap deformation. Oh, and the muscle modifiers are placed after a subsurf modifier, so that shrinkwrap has more geometry to make the deformation.

Thanks for the tips. To start with, I think I’ll simplify things by just using shape keys on the T-rex mesh, rather than modeling individual muscles. Here’s a cool pic of the T-rex musculature. It’ll be a pretty ambitious project.

Steve S