Does SteamVR support alpha transparency?

[sjacobs]

I'm trying to edit the HelloVR sample app to have a transparent background. However, it seems that SteamVR doesn't respect the alpha values submitted to the compositor, despite the pixel format being RGBA. Is there a flag that I can enable which will force SteamVR to transmit the alpha value submitted to the runtime?

I see that I can create an overlay application with alpha between [0, 1]. I would like to do the same with a scene application.

[BOLL]

What do you expect to be behind the transparent parts in this case? I think it'd just become black and not the base SteamVR environment as a scene application is rendering frames...

[sjacobs]

I'd like to underlay the passthrough camera image on the client side to enable mixed reality experiences.

[Rectus]

Unfortunately there is no support for compositor based passthrough, neither through OpenVR or OpenXR. The only way SteamVR supports passthough for applications is through the TrackedCamera interface in OpenVR, which means you need to manually reproject the camera frames.

Or use OpenXR with my API layer (that pulls the camera data from OpenVR)
https://github.com/Rectus/openxr-steamvr-passthrough