VFX+LWRP not working on latest iPad Pro

Hi I’m seeing a strange Behaviour:
I have a scene for iOS with the basic VFX swarming particles.

The scene is working perfectly on an iPad with iOS12.1 and on iPhone7 with iOS 12.3.1.

The exact same scene in tha App, built from the same Unity and XCode project does NOT showing ANY particles on an iPad Pro with 12.3.1.

XCode fires this debug message when the particles should be shown:

2019-07-12 15:35:26.592595+0200 scenaVfx[787:167140] Compiler failed with XPC_ERROR_CONNECTION_INTERRUPTED
2019-07-12 15:35:26.612826+0200 scenaVfx[787:167140] Compiler failed with XPC_ERROR_CONNECTION_INTERRUPTED
2019-07-12 15:35:26.630017+0200 scenaVfx[787:167140] Compiler failed with XPC_ERROR_CONNECTION_INTERRUPTED
2019-07-12 15:35:26.630041+0200 scenaVfx[787:167140] MTLCompiler: Compilation failed with XPC_ERROR_CONNECTION_INTERRUPTED on 3 try
Metal: Error creating pipeline state (Hidden/VFX/System 1/Quad Output): Compiler encountered an internal error

…seems to be related with the Hidden/VFX/System 1/Quad shader.

I’m using:
Unity2019.1.1f1
LWRP 5.13
VFX 5.13

EDIT: Almost the same happens with
Unity 2019.2.0B7
LWRP 7.7.1
VFX 6.7.1
VFX 6.7.1

The message here was:

MTLCompiler: Compilation failed with XPC_ERROR_CONNECTION_INTERRUPTED on 3 try

Metal: Error creating pipeline state (Hidden/VFX/System 1/Quad Output): Compiler encountered an internal error

(null)2019-07-12 16:32:33.407335+0200 vfxtest[854:182689] [BoringSSL] nw_protocol_boringssl_get_output_frames(1301) [C3.1:2][0x117b23b90] get output frames failed, state 8196

Thank you!
G.

@neurograph Did you have any luck with resolving this? Did you report a bug to unity about this issue?

Having similar problems. I have isolated the cause of the compiler errors down to the modifying properties in the output blocks, eg. “Color Over Lifetime”, “Orient”.
Still trying to find out why metal fails to compile the additional process blocks.

I finally got it working…
After days of testing and isolating the offending shader code, I found the core of the problem.
The metal compilers on iPhoneX/iPad/iPhone6 are throwing errors on evaluation of curves.
So replacing the sampling curves with gradient sampling. The errors went away.

1 Like

@weiping-toh A Hero we need :slight_smile:
@neurograph Hmmm, is there an issue open in issue tracker? It would be cool to have it fixed in the mainstream VFX code

If other people want it fixed they need to report a bug. Forum is not a bug reporter and will lead to much much slower bug fixes (whenever devs read it, which is not often, and they might be busy, but they can’t ignore proper bug reports).

1 Like

Sending a repro project through the bug reporter, along with your conclusions, would make a lot of difference in getting this fixed sooner rather than later.

1 Like

Someone had already submitted an issue about this… So how do I add more info the the issue?

Apparently, this issue might be fixed in the latest version.
https://github.com/Unity-Technologies/ScriptableRenderPipeline/blob/077648f1ead8204f07b537ae1f3c95bf8646642d/com.unity.visualeffectgraph/Shaders/VFXCommon.hlsl#L333

When the game Ran, it ran with all Blue in the background and White on Sprites or whatever that was rendered. Let me know if anyone knows how to fix it.

Here is a crash report.
CrashReporter: initialized

2019-10-12 17:45:29.359863+0530 GameName[5686:1700387] Built from ‘2019.2/staging’ branch, Version ‘2019.2.6f1 (fe82a0e88406)’, Build type ‘Release’, Scripting Backend ‘il2cpp’

2019-10-12 17:45:29.363594+0530 GameName[5686:1700387] → registered mono modules 0x103a417e0

→ applicationDidFinishLaunching()

2019-10-12 17:45:29.432234+0530 GameName[5686:1700387] Metal GPU Frame Capture Enabled

→ applicationDidBecomeActive()

GfxDevice: creating device client; threaded=1

Initializing Metal device caps: Apple A10 GPU

Initialize engine version: 2019.2.6f1 (fe82a0e88406)

WARNING: Shader Unsupported: ‘Hidden/Internal-MotionVectors’ - Pass ‘’ has no vertex shader

WARNING: Shader Unsupported: ‘Hidden/Internal-MotionVectors’ - Setting to default shader.

CrashReporter: No pending report exists at /var/mobile/Containers/Data/Application/1883F091-56AE-4DB4-AE68-0EE1AD988259/Library/Caches/CrashReports/crash-pending.plcrash

WARNING: Shader Unsupported: ‘Hidden/Internal-GUITexture’ - Pass ‘’ has no vertex shader

2019-10-12 17:45:30.163389+0530 GameName[5686:1700617] Compiler failed with XPC_ERROR_CONNECTION_INTERRUPTED

2019-10-12 17:45:30.175804+0530 GameName[5686:1700617] Compiler failed with XPC_ERROR_CONNECTION_INTERRUPTED

2019-10-12 17:45:30.188687+0530 GameName[5686:1700617] Compiler failed with XPC_ERROR_CONNECTION_INTERRUPTED

2019-10-12 17:45:30.188864+0530 GameName[5686:1700617] MTLCompiler: Compilation failed with XPC_ERROR_CONNECTION_INTERRUPTED on 3 try

Metal: Error creating pipeline state (Hidden/Internal-GUITexture): Compiler encountered an internal error

(null)2019-10-12 17:45:30.217670+0530 GameName[5686:1700387] Unbalanced calls to begin/end appearance transitions for <SplashScreenController: 0x151e34f10>.

UnloadTime: 0.626208 ms

WARNING: Shader Unsupported: ‘TextMeshPro/Mobile/Bitmap’ - Pass ‘’ has no fragment shader

WARNING: Shader Unsupported: ‘TextMeshPro/Mobile/Bitmap’ - Pass ‘’ has no vertex shader

ERROR: Shader Shader is not supported on this GPU (none of subshaders/fallbacks are suitable)WARNING: Shader Unsupported: ‘TextMeshPro/Mobile/Bitmap’ - Setting to default shader.

WARNING: Shader Unsupported: ‘Hidden/BlitCopy’ - Pass ‘’ has no fragment shader

WARNING: Shader Unsupported: ‘Hidden/BlitCopy’ - Setting to default shader.

2019-10-12 17:45:40.252580+0530 GameName[5686:1700617] Compiler failed with XPC_ERROR_CONNECTION_INTERRUPTED

2019-10-12 17:45:50.303252+0530 GameName[5686:1700617] Compiler failed with XPC_ERROR_CONNECTION_INTERRUPTED

2019-10-12 17:46:00.353346+0530 GameName[5686:1700617] Compiler failed with XPC_ERROR_CONNECTION_INTERRUPTED

2019-10-12 17:46:00.353648+0530 GameName[5686:1700617] MTLCompiler: Compilation failed with XPC_ERROR_CONNECTION_INTERRUPTED on 3 try

Metal: Error creating pipeline state (UI/Default): Compiler encountered an internal error

I copied all my assets to unity 2019.306b and built it. It worked fine this time.

**Metal: Error creating pipeline state (Hidden/Internal-GUITexture): Compiler encountered an internal error**
**Metal: Error creating pipeline state (UI/Default): Compiler encountered an internal error**

It seems that you are using incompatible shaders for LWRP, you might want to replace them.