Please update camera's position and quaternion in XR mode

[marcofugaro]

Hey, I've been trying the XR mode (specifically immersive-ar) and I have some feedback.

Currently, each time you have to get the camera's position and quaternion, you have to do it like this:

const cameraPosition = new THREE.Vector3().setFromMatrixPosition(camera.matrixWorld)
const cameraQuaternion =  new THREE.Quaternion().setFromRotationMatrix(camera.matrixWorld)

Because just the camera.matrixWorld is updated directly from the XRViewerPose, the position and quaternion are never updated.

three.js/src/renderers/webxr/WebXRManager.js

Line 415 in 043e5c9

camera.matrixWorld.copy( cameraVR.matrixWorld );

Can this be solved just by setting the position and quaternion from the matrixWorld each frame and setting camera.matrixAutoUpdate = false?

[Mugen87]

I believe this issue is related to #18448 (comment).

If so, is it okay for you to mark this issue as a duplicate and continue the discussion in #18448?

[marcofugaro]

Yeah sure. So are camera.position and camera.quaternion be updated automatically when that issue will be fixed?

[Mugen87]

Let's see how this PR goes: #19085