BabylonJS
[XR] Add ability to toggle Spectator Mode and provide configurable frame rate
Spectator Mode in XR has been recently added however there is no method to disable the spectator mode once it is enabled (apart from manually clearing the activeCameras array). I have a situation where I am streaming the spectator view to a monitoring (peer) app and, for performance reasons, I would like to be able to toggle the spectator mode on/off as required.
As mentioned, I would like to be able to toggle the spectator mode on/off so perhaps provide a parameter to the helper function to specify whether to enable/disable. In addition, because the user experience in the headset is a priority and the monitor spectator view is low priority perhaps being able to specify a lower frame rate for the spectator mode, ie it is not required to run at the full frame rate of the user in XR. So perhaps something like enableSpectatorMode(enable=false, options={}) where options can contain options.fps and the spectator canvas is only updated according to that frame rate.
Discussed with @RaananW here https://forum.babylonjs.com/t/webxr-render-canvas-and-streaming/20893/33
I am going to help work on this. If there is a spectator mode demo from Babylon.js, that would be a big help.
Spectator mode is being enabled using the experience helper. It is a single call to this function:
https://github.com/BabylonJS/Babylon.js/blob/master/src/XR/webXRExperienceHelper.ts#L218
Options variable can be added to this function, i guess?
