How to modify GLTF mesh orientation at loading?


I have a GLTF model, where the model is flipped, it is mirrored on the ZY plane.
I am using gtlfjsx to load it, the gltf contains a single mesh.
Is there an easy way to fix the orientation after loading?
I do not want to use rotation, because the model is programatically animated, and would need to update every code path, where the rotation changes.

Is there maybe a tool that is easy to worked with, to modify the model?

You may use several approaches. Here are the first two of them:

Transformation of geometry

If the model is really a single mesh, then transform not the mesh, but its geometry (use its methods rotateX, rotateY, rotateZ, applyQuaternion, applyMatrix4 – whatever means of rotation you are comfortable with).

Encapsulation in a group

Put the model in a THREE.Group. Then rotate the model’s mesh the way you want. This rotation will be relative to the group. In the rest of the program, when you move and rotate the model, do it with the group, not with the model itself.