I am developing a web application that leverages WebGL to display 3D content. The app would benefit from tracking headset movement when viewing the 2D page as a Window while wearing Vision Pro. This would ultimately allow me a way to convey the idea of the Window acting as a portal into a virtual environment, as the rendered perspective of the 3D environment would match that of the user wearing the headset. This is a generic request/goal, as it would be applicable to any browser and any 6dof device, but I am interested in knowing if it is currently possible with Vision Pro (and the Simulator) and its version of Safari for "spatial computing". I can track the head movement while in a WebXR XR or "immersive" session, but I would like to be able to track it without going into VR mode. Is this possible? If so, how and using which tools?

The Safari version for VisionOS (or spatial computing) supports WebXR, as reported here. I am developing a Web App that intends to leverage WebXR, so I've tested several code samples on the safari browser of the Vision Pro Simulator to understand the level of support for immersive web content. I am currently facing an issue that seems like a bug where video playback stops working when entering an XR session (i.e. going into VR mode) on a 3D web environment (using ThreeJS or similar). There's an example from the Immersive Web Community Group called Stereo Video (https://immersive-web.github.io/webxr-samples/stereo-video.html) that lets you easily replicate the issue, the code is available here. It's worth mentioning that video playback has been successfully tested on other VR platforms such as the Meta Quest 2. The issue has been reported in the following forums: https://discourse.threejs.org/t/videotexture-playback-html5-videoelement-apple-vision-pro-simulator-in-vr-mode-not-playing/53374 https://bugs.webkit.org/show_bug.cgi?id=260259