GLTFloader rotation with multiple nodes

[MisterblueGuy]

I've been having problems loading GLTF files that load correctly using other graphics packages. I have GLTF files that contain multiple nodes and the nodes would end up rotated oddly.

Looking at the code, there is one place where, if the rotation is specified with a quaterion (rather than a matrix) the node rotation is computed with an odd RotationFromAxis computation. If I change the code to just fetch the quaterian from array, the GLTF file loads correctly.

The lines in question is 2195 in babylong.glTFFileLoader.js:

configureNode(lastNode, BABYLON.Vector3.FromArray(translation), BABYLON.Quaternion.RotationAxis(BABYLON.Vector3.FromArray(rotation).normalize(), rotation[3]), BABYLON.Vector3.FromArray(scale));

works if it is changed to:

configureNode(lastNode, BABYLON.Vector3.FromArray(translation),
                    BABYLON.Quaternion.FromArray(rotation),
                    BABYLON.Vector3.FromArray(scale));

Does one of the GLTF loader people know why the code is the way it is, and, is this a bug?

(Also, since I'm new here, should this be reported in the GitHub issues or is this the right place?)

[GameMonetize]

Hello ping @Luaacro

This is really weird and I think that you found a bug  do you want to do a PR?

[MisterblueGuy]

I'll do a PR shortly. Thanks.

This could be related to the other rotation discussion as it would only happen if the node's rotation was specified as a quaternion. If it was passed as a matrix (as it is in all of the example objects), one would not see the problem.

 

[GameMonetize]

makes sense (and PR merged)