quaternion interpolator has numerical problems
This issue was created automatically from an original Mantis Issue. Further discussion may take place here.
I think the quaternion interpolator is using operations which're numerically unstable as the orientations approach one another. In particular, vtkQuaternionInterpolator::InnerPoint() will return an undefined orientation for very similar (just equal?) inputs.
This will demonstrate the issue: vtkTransformInterpolator* interp = vtkTransformInterpolator::New(); vtkTransform* x = vtkTransform::New(); x->Identity(); interp->AddTransform(0, x); interp->AddTransform(1, x); interp->AddTransform(2, x); interp->InterpolateTransform(0.5, x);