[Bf-committers] Muscle Rigging MVP implementation

[Zack Drach]

Hello Blender developers,

About 6 months ago, I implemented native muscle rigging in Blender for a
class project at my university. Although it's not production ready, I
figured that my code and design could help guide the decision to add muscle
rigging to Blender.

At a high level, used the algorithm described here:
http://cg.skeelogy.com/research/simplified-muscle-dynamics.php . I found
the link to the paper in the GSOC 2013 ideas document.

In terms of code modifications, I created a new DNA data structure called
Muscle, and created some operators for creating muscles and attaching them
to Bones. Integration with WeightPaint/Pose mode was also implemented.

My final report (for the class) can be found here:
http://zdrach.com/New%20Projects/01%20Muscle%20Rigging/files/report.pdf

And the diff can be found here:
http://zdrach.com/New%20Projects/01%20Muscle%20Rigging/files/diff.txt

The design looks like it should work. The main blockers for implementation
are 1) development resources (probably a couple hundred man hours) and 2)
code complexity (eg. maybe it's worth cleaning up some of the armature code
before adding muscles).

If muscle rigging becomes a development priority, hopefully these resources
should help out. (Maybe these files can be put on the ideas wiki page?)

Thanks,
Zack Drach