KhronosGroup
Missing scene support in object model and KHR_node_visibility
Looking over the object model, KHR_interactivity and KHR_node_visibility, it feels like things are underspecified for scenes.
The object model is missing a way to read an asset's default scene or a scene's nodes. Further, there's no way to know which scene is visible, which will ultimately control whether a given node can be visible or not.
It feels like KHR_interactivity needs a notion of the visible scene, which may be the implicit scene defined by all nodes in the asset, and KHR_node_visibility should probably also be applicable to scenes to indicate which scene is visible or not.
glTF files with multiple scenes is a niche feature, one that most implementations don't bother supporting, most extensions don't consider, and in issue #1542, this is considered being removed if there is ever another glTF compatibility breakage. I think it's good that KHR_interactivity and KHR_node_visibility don't utilize the multi-scene feature.
While I'd love a future where scenes are deleted from glTF and are only permitted in something like glX, we're not there now. I'd prefer that the current extensions support the current spec.