BABYLON.BoneIKController With GLTF Mesh

Not sure how the API is structured, but also not clear if absoluteRotationQuaternion uses .rotationQuaternion. If .rotationQuaternion is null, this would break

Makes sense but may I ask what none desired side effects the intermediate scale is having ? I am still confused of why not keeping it in as we do for the root node ?

Here is a tentative PR: Add IK support for linked transform nodes by sebavan · Pull Request #11017 · BabylonJS/Babylon.js · GitHub