Avoid console warnings when using WebXR Layers #22145
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| needsUpdate = true; | ||
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| } // else avoid https://github.com/mrdoob/three.js/issues/22079 when using XR layers. |
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Can you explain in more detail why this fixes the mentioned warnings? TBH, I understand the change so far.
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I'm not sure of the exact flow. But I think the issue is that the system is trying to draw to _gl.BACK when using XR Layers rather than to the WebXR compositor's provided texture. I thought this would result in an error and a black frame since the draw calls would not be sent to the WebXR compositor's render target, but it only seems to be a warning.
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Sorry, I can't approve this PR without a closer study of the code. One should also clarify if this is an issue in Oculus Browser.
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That's understandable. I restricted the code as much as possible so that it only affects devices with layers. At the moment, that's limited to Oculus Browser so there is no other way to test this.
Another option might be to set renderTarget when in WebXR or when layers are active. That would cause the code to go through the if ( renderTarget ) { path above this change. I'll try making that change and see if the results are the same.
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The specific issue is that drawBuffers([gl.BACK]) is only valid for the default framebuffer that you get from bindFramebuffer(..., null). However, in WebXR mode, state.bindFramebuffer(..., null) has an override to replace the default framebuffer with the XR framebuffer which is a framebuffer object, and that should use [gl.COLOR_ATTACHMENT0] and not override with [gl.BACK].
This is a general issue that happens when switching render targets while in XR, so it's not specific to WebXR Layers. It also happens when rendering shadows in phone AR mode.
See google/model-viewer#2769 (reply in thread) which has some more details from where I investigated this for model-viewer.
Adding a "is in XR" conditional here would work, but alternatively would it make sense to move the low-level drawBuffers call to WebGLState and apply an override there that replaces gl.BACK with gl.COLOR_ATTACHMENT0 when xrFramebuffer is active?
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Discarding this change in favor of #22558 |
Fixes #22079
Tested: