Big display bug in Babylon on new devices

[Vousk-prod.]

Hello forumerz,

 

On last generation tablets, there is a enormous display bug in Babylon.js.

This looks like some z-depth flickering, but not sure if it's related.

 

See attach files.

 

This problem doesn't occur with previous tablet generation, only the new one (tested on every new device at la Fnac, problem happen on every model… argl)

 

Works on :

ASUS Transformer Prime TF201 - android 4.1.1

ASUS MeMO Pad 10 (ME102A) - android 4.2

 

Bug on :

SAMSUNG Galaxy Tab 10.1 2014 Edition - android 4.3

many current devices in shops

 

 

[davrous]

Hello,

 

 This is interesting. Have you tested in Chrome on this Android 4.3 tablet? If so, could you please check if Firefox has the same rendering bug on the same tablet?

 

 2 options:

 

 1 - there is a bug in their WebGL implementation on Android 4.3, rather software in Chrome rather in the GPU driver. But as you say that several Android 4.3 have the same problem, it would be more Chrome related. That's why, testing on Firefox could be helpful.

 2 - some of our shaders have problems on Android 4.3 for an unknown reason.

 

Bye,

 

David

[tuan kuranes]

@davrous Chrome 31 did have a zbuffer precision bug (https://code.google.com/p/chromium/issues/detail?id=285400).

Otherwise tested on nexus 7:

http://babylonjs.com/Scenes/Robot/index.html :

=> ok on android 4.4/ chrome 34

=> not ok android 4.4/ ffx 29 (only the blue holodeck semi-transparent thing visible) and nothing at all on ffx beta 

[GameMonetize]

Can you try to play with camera.minZ and camera.maxZ

 

(for instance try tro increment minZ and reduce maxZ)

[Vousk-prod.]

I've tested with Firefox and with the builtin browser on this Android 4.3 tablet. Both display the same bug.

And during my tests on many new devices in shops, I've also tested with builtin and Firefox, and same problem.

So it seems more GPU related than browser related.

 

I haven't tested with Chrome, because Chrome require to activate advanced option on tablets to be webgl compliant, this is too complicated to do in shops

 

Tomorrow I'll test while changing camera.minZ and camera.maxZ values.

[Vousk-prod.]

Setting proper values for camera.minZ and camera.maxZ solves the problem.

 

(the bug remains problematic for all the demo scenes on bjs home page unless these values are corrected for each of them...)