Feature request: apply transform to model

My use case for this is that poly models come with presentationParams data:

"presentationParams": {
        "orientingRotation": {
            "x": -0.7071067811865475,
            "w": 0.7071067811865476
        },
        "colorSpace": "LINEAR",
        "backgroundColor": "#4caf50"
    }

In most cases it’s just:

"orientingRotation": {
  "w": 1
},

and the model is correctly oriented. However for some models (like the one above with w="0.7...") the model will load with incorrect orientation and I’d like to be able to fix that.

This could also be used to transform models between coordinate system or fix incorrectly scaled models.

[donmccurdy]

As a script this should work:

const scene = document.getRoot().listScenes().pop();
const rootNode = document.createNode('SceneRotation').setRotation([-0.707106, 0, 0, 0.707106]);
scene.listChildren().forEach((node) => rootNode.addChild(node));
scene.addChild(rootNode);

Does that seem workable? glTF does specify how a scene is supposed to be oriented, so I’d rather not add a built-in function to convert to other coordinate systems.

[donmccurdy]

• Filed as https://github.com/donmccurdy/glTF-Transform/issues/579