Quaternions

Quaternion Rotation Input to RBF Solvers
Feb 3, 2020 Maya Rigging Python C++ Maya API RBF Quaternions
In my previous post, I described how to create an RBF solver using regularized linear regression. While the solver works well for most independent input values, it does not work so well if we want to drive it with euler rotations. Euler rotations are susceptible to gimbal lock and can have multiple solutions for the same rotation. These two joints look like they have the same rotation. But looking at their animation curves tells a different story: