📦 Bundle size

Full ESM build, minified and gzipped.

🌳 Bundle size after tree-shaking

Minimal build including a renderer, camera, empty scene, and dependencies.

/cc @cabanier

Just in case it's useful, see #26340

This PR causes layer=1 and layer=2 to be both activated for the XR camera. See the following two issues:

• https://discourse.threejs.org/t/a-possible-bug-with-object3d-layers-in-webxr/77256/3
• Setting mesh.layers.set(1) does not work pmndrs/xr#398 (comment)

The PR just ensures to retain an existing layer configurations of the non-XR scene camera. That was a annoying issue in the past and fixed with this PR.

This PR causes layer=1 and layer=2 to be both activated for the XR camera

This was also true before this PR was merged. Do you mind explaining in more detail the regression that you are facing?

The cause of the issue has been found (see pmndrs/xr#398). For context, the issue lies in @react-three/xr where the XR camera is being fed back into the render call, effectively doing:

renderer.render(scene, renderer.xr.getCamera());