playcanvas / playcanvas/engine

WebXR AR - Opacity Blending

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Dominant language
JavaScript
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Description

There is some issue with the way opacity is blended when using WebXR AR session. This happens in the emulator and on devices (Android, Quest 3, etc).

It looks like alpha is not accumulated, but the last rendered fragment alpha is written.

Camera clear color is 0,0,0,0. Body CSS background color is 0,0,0,0. Canvas background color is 0,0,0,0.

Test URL: https://playcanv.as/e/b/70c1ec2f

Normal:

image

In WebXR:

image

Contributor guide

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First steps

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  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by reproducing the opacity difference at the linked test URL in the Immersive Web Emulator and on a reported Android or Quest 3 device. Compare the WebXR AR rendering path with the normal path, focusing on the stated alpha accumulation behavior. Done means transparent AR rendering blends correctly across the listed environments; no source file or test is named in the issue.

Written by the indexing model from the issue text.

Assessment

Tech stack
javascript
Domain
ar-vr-xr
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
28/100

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