MeshStandardMaterial iOS rendering issues

Hi there,

I think I might have found a bug on iOS. I have a MeshStandardMaterial working with a texture for its roughness(green), metallic(blue) and AO(red) channels…

In my case AO is not used, so red channel is empty. This causes iOS to render incorrectly or at least completely different than any other platform including Safari on OS X, Android, Chrome, etc. The resulting rendering on iOS is completely dark. If I remove the aoMap linkage to texture the render is then fixed, but shouldn’t it be ignored like in other platforms?

Unfortunately I can’t share this particular example right now cause it is for a commercial project under development but can try to put another example online if you can confirm this is a bug.

Many thanks!

[jocabola]

Yes, it is a PNG and it does look like it could be a premultiplied alpha issue.

[jocabola]

Hello,

Thanks a lot for your feedback. I have been isolating a simpler example and I wasn’t able to longer reproduce this behaviour…

After digging a bit further in, turns out that it might be related to the texture I was using since this had an alpha channel which is probably messing with the RGB channels in iOS somehow. If I don’t have a transparent background the behaviour in all platforms is identical but if there is an alpha channel (even not affecting the rendered surface) things go funky on iOS. Getting very different results. Perhaps this is a known behaviour already. Nevertheless it will be a different bug then and I should do a bit more testing before posting a new issue. Also, it makes no sense to have transparent pixels on a PBR texture for roughness/metalness/AO.

Thanks and sorry for the misleading initial post!