Rendering regression from v1.9.0 of Mixed Reality OpenXR Plugin

[lukefanning]

Hi,

After upgrading from v1.4.0 to v1.11.2, I immediately noticed some kind of rendering issue in our game DEVOUR. The issue only presents itself in a standalone build when running under the Mixed Reality OpenXR runtime. It's fine in the editor. Here are some screenshots:

v1.8.2:

Here you can see the main menu canvas in world space and then the menu environment off to the left side with the fog etc.

v1.9.0:

Here you can see that everything looks normal where the canvas is but outside of the canvas is extremely dark but not black i.e. if you look hard enough you can just about make out the environment.

Any ideas what might have caused this?

We really wanted to get onto v1.11.2 after the issue I reported was resolved (#178)

[lukefanning]

I looked into this again today and found it was caused by FXAA. The fix or workaround is to enable Keep Alpha under FXAA settings (something that wasn't necessary pre-1.9.0). This issue does not occur with SMAA or TAA.