When I drag, the rotationQuaternion changes. Why is this happening?
this is PG ( Babylon.js Playground (babylonjs.com))
Hello!
This happens because the root node of the alien mesh has a negative scaling. When the mesh is translated, the transformations are recalculated, and for this specific case, the combination of scaling + rotation is recalculated as a different combination with the same result. The negative scaling of this root node happens because the GLTF format is right handed, while Babylon is left handed, so it’s necessary to convert between coordinate systems.
Since the negative scaling is only required for this change of coordinates, if you set useRightHandedSystem to true in the scene, the root node won’t have a rotation + scaling, and it won’t change when you move: https://playground.babylonjs.com/#JA1ND3#886
4 Likes
Okay. I thought this was not expected
Thank you for your help