Unable to create uniform buffer on ios17

On iOS 17 developer beta (beta 8), on tablets only (presumably a problem with iPadOS):

If you open up the babylonjs playground (just the empty one https://playground.babylonjs.com/) and background it while it is loading (blue screen, spinner around babylonjs logo), and then bring it back to the foreground, the webgl scene fails to create and we get an error “Unable to create uniform buffer”, and the webgl context is hosed. This error was not present in beta 7.

We are seeing this in our applications as well when backgrounding them (we are on version 5.7.0 of babylonjs, but can reproduce it even when upgrading locally). For our applications, this also happens periodically when we background them even after they are already initialized.

I’m sure this isn’t an issue with BabylonJS itself, but with iOS, but we are struggling with figuring out the “why” so we can work around it, and were hoping someone inside of BabylonJS may have some knowledge of where to look since we can reproduce inside of the playground.

Unfortunately I am not sure you can workaround it :frowning:

The best is probably to open a ticket on the webkit bug tracker.

You could also try to change the backend in the safari flags to see if it is enough for now. I am sorry I can not help more…

Sorry, can you explain more of what you mean by “change the backend in the safari flags”?

In the safari options in advanced/experimental features, there are a couple options you can try to switch back and forth (webgl 2.0 and webGL via metal)

Oh yeah we tried that. Very oddly, it did not fix the playground, but did seem to (mostly) fix the issue in our site, obviously at the cost of visual quality.

Thanks for the help, we have posted bugs/forum posts with apple, I will post back here if any answers come through.

You can try to set engine.disableUniformBuffers = true to instruct the engine not to use uniform buffers.

No luck with that, unfortunately