How to rig a chain

by hazmondo posted 721 days ago | 1 comment

Hey,

I'm wondering if anyone has any knowledge of creating a complex chain rig similar to the one in Kung Fu Panda 3 (https://www.youtube.com/watch?v=aq5NcuEOwjw)? They obviously used a mixture of animation and simulation.

At the moment I'm using an FK to drive a ribbon which has sub controls for offsets but I'm not sure it's enough.

by RickFronek posted 225 days ago

Hi, For situation like these, we would normally use a decent rope rig, meaning a setup that has positional and rotational ability. Some sort of combination of FK and SplineIK where FK would be dominant to IK. Child/Parent relationship. This setup must have stretch ability as well. Your ribbon approach might be enough. Having a modular system that enables you to quickly rebuild your setup is crucial, but not 100% necessary. It maybe enough. Push it through some animation stress tests.

The setup usually goes through few iterations to make sure the animators have enough control density so they can accomplish requested animation with the setup. Some high level places may spend time building a system that has the ability to dynamically insert more controls as the rig gets into poses that requires more anim controls. But that's usually an overkill for most rope animations.

The other part of the setup would be a secondary dynamic rig that will handle the nice collisions and follow through. This setup takes the incoming nurbs curve that drives the splineIk and we use it as input curve that drives are dynamic setup. Then it's just matter of understanding how dynamics work and run a secondary pass on top of approved animation.

Simply put, animRig > approved animation > dynamic pass on top of the anim > final result.

There are always multiple ways to skin the cat, this would be mine. :) Hope that helps a bit.

-R