GLTF root not included in list of entities

[vorg]

Synthetic root we create for the loaded scene is not included in the list of scene.entities. That causes problems when trying to find certain components like Animations

const scene = renderer.loadScene(url)
scene.entities.filter((e) => e.getComponent('Animation')) // -> length 0
root.getComponent('Animation') // -> Animation

Adding root to entities array would solve that issue but in a way it modifies the gltf file which might be unexpected.

[vorg]

It seems that one of the reasons to have root in the first place is that animations don't belong to any particular node and are considered part of the scene. In our case root entity takes role of the scene.

[vorg]

IBL lights will be also defined at the scene level https://github.com/KhronosGroup/glTF/tree/821b2bd58bfc400e575d37fce77bf5cf47dec531/extensions/2.0/Vendor/EXT_lights_image_based#adding-light-instances-to-scenes

The question if scene.root should be part of scene.entities (ideally scene.entities[0]) remains. @dmnsgn ?