[Gear VR] Support Low Quality Lightmap shader permutations option crashes app

Apparently a nasty bug in UE 4.14.1. If I disable “Support Low Quality Lightmap shader permutations” option in the Project Settings > Rendering (a way at the bottom), the app will crash on Gear VR (it shows black screen and goes straight into Oculus Home).

With “Support Low Quality Lightmap shader permutations” no crash happens and apps runs normally (presumably).

Running ES2 build, full rebuild, Android 6.0.1, Galaxy S6

Oh, I see. Didn’t know that. Maybe just adding a tool tip or something that it’s not for mobile would be a good idea? (or maybe putting it in the docs)

Thanks for the tip, I’ll try to do that next time I get a crash on Android.

Hey Motorsep,

HQ_Lightmaps, which are forced for use when you disable this option, is not meant for Mobile platforms. Mobile uses LQ_Lightmaps. You can use the option for “Uncompressed Lightmaps” in the World Settings, but that will increase their cost significantly (by at least 4x!).

Also, this is not a GearVR specific or 4.14.1 specific issue as I was able to quickly repro in 4.13.

When getting App crashes with your game make sure to use the Android Device Monitor to filter out the UE4 crash and you can read the log there. You can do this by following the steps below:

  • Using Android Monitor App
  • Go to C:\NVPack\android-sdk-windows\tools
  • run the Monitor.bat file
  • Connect your device to your PC (you’ll need to have the Android in Developer Mode for the GearVR services so that you don’t need the headset)
  • Run the app and get the crash to happen
  • Save the logs and upload here in a text file

-Tim

At that point, we’d have a lot of tooltips that just said not supported for mobile. It’s probably a better assumption that it’s not supported unless said otherwise. If you’re unsure the source code is available to dig through or post questions asking about its support. :slight_smile:

The android device monitor is a really helpful tool, especially for mobile development and seeing what’s generated in the log when you get a crash. It’s really a must use tool.