Three.js: WebVR panorama and video examples are not mirrored

[cvan]

Description of the problem

1. Load https://github.com/mrdoob/three.js/blob/dev/examples/webvr_panorama.html and https://github.com/mrdoob/three.js/blob/dev/examples/webvr_video.html in the Chromium WebVR builds
2. Notice upon clicking "Enter VR" the content is not mirrored (but is presented to the VR display properly)
   

   Three.js version

• [x] Dev

  Browser

• [x] Chromium WebVR Oculus build (April 6, 2016)

[MasterJames]

You're pointing to files in the master branch but maybe thsee issues are different in the development branch dev already?

[cvan]

You're pointing to files in the master branch but maybe thsee issues are different in the development branch dev already?

Sorry, I meant to link to dev files; was testing there. Fixed URLs.

[mrdoob]

Isn't this a bug in Chromium?

[cvan]

Isn't this a bug in Chromium?

Is it? I don't know. @toji?

[toji]

If you want content mirrored to the external display the code either needs to re-draw the scene after calling submitFrame or set { preserveDrawingBuffer: true } in the context attributes when creating the WebGL context. Also note that you should only mirror content when vrDisplay.capabilities.hasExternalDisplay == true, because otherwise there's no display to mirror to. (Like Cardboard)

[tbalouet]

I just experimented the same problem on Edge with current builds. Adding the "preserveDrawingBuffer:true" in the renderer fixes the problem (found out via Samira Hidji through this conversation: https://twitter.com/samirahirji/status/1034139068651560963)

Is this a normal behavior? If so, why does it work on Firefox without the preservedrawingbuffer but not on Edge?
Test use case:
Without preserveDrawingBuffer: https://glitch.com/~six-galley
With preserveDrawingBuffer: https://glitch.com/~grave-hovercraft

[mrdoob]

Is this a normal behavior? If so, why does it work on Firefox without the preservedrawingbuffer but not on Edge?

I guess you should ask Microsoft people instead?

[mrdoob]

@toji does WebXR also need preserveDrawingBuffer: true?

[tbalouet]

I guess @SamiraAtMicrosoft might be able to let us know if there's any insight on the fact that it only occurs on Microsoft HMDs

[SamiraAtMicrosoft]

This behavior was implemented in Edge to avoid drawing the canvas to the web page unnecessarily while immersed in WebVR.

[mrdoob]

Working as intended then 👌