CloudXR 3.1 Too dark in ArCore sample


I tried updating our Android ArCore CloudXR viewer (based on the hello_cloudxr sample) to v3.1 today.

The connection and setup is fine, but the image I’m getting on the Android handset looks too dark. It’s like the colour space is wrong - at a guess I would say it’s expecting gamma, but getting linear (for example).

I’m also having the problem where the alpha layer appears to be too low a value… I can see the camera background even in areas where I expect it to be opaque.

Is there a workaround, or a fix in the works?


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Yes, we unfortunately identified this too late in our release process. I believe there’s a bullet for the bug in the release notes.

And yes, it looks to be a problem with gamma vs linear. Not yet clear if it’s driver variants handling things differently. We have to do gamma->linear for decoded frames on the android VR headsets, as somewhere the drivers aren’t properly detecting gamma. That seems to not be working for android AR devices.

We’re looking into the cause of the difference, and the right longer-term solution. We’ll also take a look at whether there is any quick, temporary work-around that could be done on the sample side (as this piece is inside the library, we’d need to replicate the blit code, like the ARCore sample did in the earliest releases).

I don’t have any ETA at the moment unfortunately.

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Thanks Dave. Good to know you’ve identified the issue.

We actually never got rid of our blitter.h/.c so wouldn’t be too afraid of a change to the shaders to sort it out. Or we can just wait for 3.2.

Hi there, to follow up on this issue, I was just testing 3.1.1 and it looks really sharp / good, but we’re not sure if the gamma and colour space issues are fixed yet?

The colours and sharpness look much nicer to me in daytime scenes here, but it could simply be over-saturated. It’s also too dark at night and in dungeons, but it seems much better overall.

Could it be having black crush due to limited → fullrange expansion? Or maybe just the wrong gamma curve / tonemap.

Here’s a comparison of SkyrimVR on 3.0 (LEFT) vs 3.1.1 (RIGHT):

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No, we had other critical stability issues that were behind 3.1.1 hotfix release, this wasn’t even on the list. Should be for the next main release. Main issue is whether we can programmatically determine when/why there is the CSC difference in ARCore, and then maybe remove the extra conversion. Also possible there is just a different code path for ARCore (which does the alpha blit) which is causing an incorrect state to get set and handled. Images certainly look like a gamma->linear ‘crush’.

It’s on the list, we’ll review when it comes up on the backlog of tasks.

Hey Dave, I just tried CloudXR 3.2 to see if the toggle helps and it doesn’t appear to be necessary, at least for SkyrimVR to look good. So without using that new flag to force linear (which makes it way too bright), the full sRGB end to end rendering pipeline seems optimal now and my brightness settings were just set too low in the game menu.


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