To improve the quality of our in game UI, we recently moved it from world space widgets to Stereo Layers.
However, transparent Stereo Layer have black backgrounds on the quest where it is supposed to be transparent. After setting up the stereo layer, so that it gets live textures from the Unreal UMG system, the transparent parts appear black on the Quest.
So here how it looks on the Quest:
And how it looks on the PC with oculus link and VR preview in engine (this is how it is suppose to look):
The issue only pops up with Live textures, if I place a sprite with alpha channel as the texture, it is displayed correctly with alpha blending.
One thing we have already tried is creating the render target in C++ and ensuring that the clear color has the alpha of 0, so (0,0,0,0) and the format supports RGBA.
The issue here seems to be (at least I think trying to repro this on my end) not the live texture portion of this (transparent live textures stereo layers seem to work fine), but the fact that you checekd SupportDepth (which in the current implementation doesn't support transluency). Can you confirm?>