gltf 2.0 model show dark side in android device

[Chris Wang]

Hi everyone

I have made an application for web browser to load my own gltf2.0 model.

It looks great. Now I want to move the application to my android device (Samsung S8).

But the model looks dark on the other side of the sun light.

The first picture is the browser look, and the second one is effect in my android device. 

I also upload the glb file below.

Any help is appreciated.

Thanks

Chris

[Sean Lilley]

It looks like the timeline for both screenshots are at the same date, so I'm confused why it looks light in one and dark in the other. If you explicitly set the clock to a certain time does the model look the same in both?

[Chris Wang]

Hi Sean, the time is the same in both scene.  But the model in android device is much darker than the model in browser.

[Chris Wang]

Hi Sean

The problem is still there when I set the clock at the same time.

在 2018年5月10日星期四 UTC+8上午7:26:03，Sean Lilley写道：

[Sean Lilley]

That's really strange. Does this happen for all models you try? Do you notice the same problems on other mobile devices?

[Chris Wang]

Yes Sean, it happens for all the gltf2.0 model. I've try the pbr demo in the online Sandcastle. The model is still dark on the other side of the sun light.

model on windows pc browser looks great

on samsung S8(SM-G9500) default browser

I also try another android phone, and it looks dark as well.

But the model looks well in the iphone browser.

Any help is appreciated. 

Thanks

在 2018年5月18日星期五 UTC+8上午1:56:09，Sean Lilley写道：

[Chris Wang]

By the way, I alse try Chrome and Firefox browser on my android phone. It looks dark as well.

The model only looks well in iphone safari browser. 

[Sean Lilley]

I'm still not sure what's going on, but I opened an issue on github: https://github.com/AnalyticalGraphicsInc/cesium/issues/6622.

Hopefully others can test and help debug the problem. If you are willing to dig in closer, try making adjustments to the shader in processPbrMetallicRoughness. I suspect the problem is there somewhere.

[Chris Wang]

Thanks Sean, I will try to figure out the problem.

在 2018年5月24日星期四 UTC+8上午10:34:53，Sean Lilley写道：

[alx...@gmail.com]

在 2018年5月24日星期四 UTC+8下午2:48:23，Chris Wang写道：

Did you slove the problem? My 3D Tiles models looks dark on Android. I have disable shadows in viewer and Cesium3DTileset. But did not work.

https://github.com/alx696/share/raw/master/image/3DTiles%E5%9C%A8%E7%94%B5%E8%84%91%E4%B8%8A%E6%95%88%E6%9E%9C.png

https://github.com/alx696/share/raw/master/image/3DTiles%E5%9C%A8Android%E4%B8%8A%E6%95%88%E6%9E%9C-%E5%8F%B3%E8%BE%B9%E9%BB%91.jpg

https://github.com/alx696/share/raw/master/image/3DTiles%E5%9C%A8Android%E4%B8%8A%E6%95%88%E6%9E%9C-%E5%B7%A6%E8%BE%B9%E4%BA%AE.jpg

[Ian Walberg]

Was there an explanation to this issue? We see the same on certain Android devices.

Thanks

[Omar Shehata]

I believe we've isolated the issue to a driver bug on these Android devices, see this GitHub issue: https://github.com/AnalyticalGraphicsInc/cesium/issues/7651

I was waiting on an external contribution to fix this, but I might just go ahead and open a PR with the fix so we can get it in time for the next release.

[Omar Shehata]

This has been fixed, and will be available in CesiumJS 1.59 that's coming out next week!