URP build always crash when 'Use SPR Batcher' is ON by default

Include the following details while filing a bug report (edit as applicable):

  • Issue category: ARMeshManager/Mesh Generator
  • Device type & OS version: Android
  • Host machine & OS version: Mac
  • Issue Environment : On Device
  • Xcode version:
  • ARDK version: 2.5.2
  • Unity version: Unity 2021.3.29f1

I hope it helps who are using URP and struggling with a crash on device when generating meshes.
A simple workaround to resolve the crash is to turn off ‘Use SRP Batcher’ option in ArdkUrpAsset.
The option is usually ON by default.

Bug reproduction steps:

With URP,

  1. Use a material with the following custom shader created by shadergraph for AR Mesh
    GeneratedFromGraph-ShadowReceiverMod.shader (64.7 KB)

  2. Select ArdkUrpAsset

  3. Switch Inspector mode to Debug

  4. Search ‘Use SRP Batcher’, by default it is usually ON.

  1. If the option is ON, app crashes 100% while generating mesh via ARMeshManager.
  2. Stacktrace shows it happens at GfxDeviceGLES::DrawBuffersBatchMode
  3. I tested ‘Dyanmic Batching’ option and a relevant Tag - ‘Disable batching’ in some shader, it doesn’t matter. It is nothing to do with Dynamic batching, but it’s turned out to be SRP Batcher.

Crash log is as follows.

*** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
Build fingerprint: 'google/bluejay/bluejay:13/TQ3A.230805.001/10316531:user/release-keys'
Revision: 'MP1.0'
ABI: 'arm64'
Timestamp: 2023-08-29 14:50:18.669731330+0800
Process uptime: 72s
Cmdline: {*** bundle_identifier ***}
pid: 29110, tid: 29296, name: Thread-8  >>> {*** bundle_identifier ***} <<<
uid: 10380
tagged_addr_ctrl: 0000000000000001 (PR_TAGGED_ADDR_ENABLE)
signal 11 (SIGSEGV), code 2 (SEGV_ACCERR), fault addr 0x0000007170400000
    x0  0000005efe084840  x1  00000071703fffe0  x2  00000000000000e0  x3  0000005efe084980
    x4  0000007170400110  x5  0000005efe084af0  x6  0000000000000000  x7  0000000000000000
    x8  0000000000000000  x9  0000000000000000  x10 0000000000000000  x11 0000000000000000
    x12 0000000000000000  x13 0000000000000000  x14 00000071801877f0  x15 0000000000000023
    x16 00000072adc7acf0  x17 00000075d6bc2f20  x18 00000071abd18000  x19 0000000000000010
    x20 0000007246dd52c0  x21 0000000000000022  x22 00000071703ffe60  x23 0000005efe084840
    x24 00000000000002b0  x25 b40000741a52cc50  x26 00000000000002b0  x27 00000071d0457670
    x28 00000071ac848950  x29 00000000000000a0
    lr  00000072ad146c0c  sp  00000071ac848690  pc  00000075d6bc2ecc  pst 0000000020001000
      #00 pc 000000000004eecc  /apex/com.android.runtime/lib64/bionic/libc.so (__memcpy+284) (BuildId: dc4001c2ef2dfc23467040797a96840c)
      #01 pc 000000000193cc08  /data/app/~~tj3lv7b-WWtkzM1sYJ1rVw==/{*** bundle_identifier ***}-EdsH-Q3L1jgEYnGIt8Obpw==/lib/arm64/libunity.so (**GfxDeviceGLES::DrawBuffersBatchMode**(GfxBatchHeader const&)+184) (BuildId: 8ceca445f342b58f)
      #02 pc 0000000001b42070  /data/app/~~tj3lv7b-WWtkzM1sYJ1rVw==/{*** bundle_identifier ***}-EdsH-Q3L1jgEYnGIt8Obpw==/lib/arm64/libunity.so (GfxDeviceWorker::RunCommand(ThreadedStreamBuffer&)+29236) (BuildId: 8ceca445f342b58f)
      #03 pc 0000000001b3add8  /data/app/~~tj3lv7b-WWtkzM1sYJ1rVw==/{*** bundle_identifier ***}-EdsH-Q3L1jgEYnGIt8Obpw==/lib/arm64/libunity.so (GfxDeviceWorker::RunExt(ThreadedStreamBuffer&)+84) (BuildId: 8ceca445f342b58f)
      #04 pc 0000000001b3ad78  /data/app/~~tj3lv7b-WWtkzM1sYJ1rVw==/{*** bundle_identifier ***}-EdsH-Q3L1jgEYnGIt8Obpw==/lib/arm64/libunity.so (GfxDeviceWorker::Run()+140) (BuildId: 8ceca445f342b58f)
      #05 pc 0000000001b3aafc  /data/app/~~tj3lv7b-WWtkzM1sYJ1rVw==/{*** bundle_identifier ***}-EdsH-Q3L1jgEYnGIt8Obpw==/lib/arm64/libunity.so (GfxDeviceWorker::RunGfxDeviceWorker(void*)+4) (BuildId: 8ceca445f342b58f)
      #06 pc 0000000001069f64  /data/app/~~tj3lv7b-WWtkzM1sYJ1rVw==/{*** bundle_identifier ***}-EdsH-Q3L1jgEYnGIt8Obpw==/lib/arm64/libunity.so (Thread::RunThreadWrapper(void*)+1048) (BuildId: 8ceca445f342b58f)
      #07 pc 00000000000c226c  /apex/com.android.runtime/lib64/bionic/libc.so (__pthread_start(void*)+204) (BuildId: dc4001c2ef2dfc23467040797a96840c)
      #08 pc 0000000000054a30  /apex/com.android.runtime/lib64/bionic/libc.so (__start_thread+64) (BuildId: dc4001c2ef2dfc23467040797a96840c)

ARDK 2.X is not supported in Unity 2022.
You should be able to ise the 3.0 beta without issue

Hi Dylan Smit,

  • As mentioned in the report, I’ve already tested Unity2021.3 which is the official support version. The issue doesn’t matter with the Unity version.
  • It is confirmed that Unity2021.3 has the issue.
  • In order to avoid any configuration just in case, I’ve removed the version info of Unity2022 which was my own test for experiment.

Oh interesting. I’ve never had issues with it.
Could you share the urp asset and urp renderer settings?
And maybe player settings are helpful.

Otherwise 3.0 beta should still work if the project is planned to release on a later date

As for those ArdkUrpAsset and PlayerSettings, there’s nothing special. They keep almost default settings.

Instead, I should’ve pointed out that it could depend on some correlation between a certain shader and SRP batcher.

I’m trying to use ShadowReceiver shader to render AR Meshes. Probably the crash is linked up with correlation between the shader and SRP Batcher.

The following is the generated shader code from the shadergraph for reference.
The subshader Tag “DisableBatching” does not have any effect as mentioned above.

The attachment is a generated shader script from the shadergraph for reference.
GeneratedFromGraph-ShadowReceiverMod.shader (64.7 KB)

I’ve updated the original post too

So it does work without the shader?

If so, maybe try one of my shaders

Thanks for the suggestion. By the way, without SRP batcher option, all is okay now. It doesn’t seem to affect any other features so far. That’s probably because my app is still very beginning that many further features have yet to be implemented.

There would be some workarounds to avoid the issue like using your shader.

I’ve reported it because I’d like to see if it’s a ARDK bug or Unity Bug, or if some particular shader function is just incompatible with ARDK. I haven’t digged deeper in that shader though to see even if it’s a shader bug.

Srp batcher can greatly improve performance, especially on mobile, so it would be great to get it working of the project will grow

I found my build pipeline was messed up, and it referred to different version of Unity instead of 2021 for the previous build process. I have fixed it and trying to rebuild it properly. And then I will test this issue for Unity2021 and update the post again.

Hi Jeremy,

I followed the steps you provided on a fresh project and didn’t encounter any issues with an iPhone 13 Pro running iOS 16.1.2. I will get some telemetry on an Android device later today and will get back to you; however, as you mentioned, it sounds like something isn’t quite right with your specific render pipeline settings.

Kind Regards,
Maverick L.