HDRP build: Cannot create required material because shader is null

I've finished migrating my game from Unity 2018.3 to Unity 2019.1, with HDRP 5.13. The game builds, but when running it, it hangs on the splash screen. Looking at the log file, I see it's throwing errors related to being unable to instantiate some materials:

Spoiler: Errors

Cannot create required material because shader is null
UnityEngine.DebugLogHandler:Internal_Log(LogType, LogOption, String, Object)
UnityEngine.DebugLogHandler:LogFormat(LogType, Object, String, Object[])
UnityEngine.Logger:Log(LogType, Object)
UnityEngine.Debug:LogError(Object)
UnityEngine.Rendering.CoreUtils:CreateEngineMaterial(Shader) (at C:\Users\Dan\Documents\GitHub\Gravia\Library\PackageCache\com.unity.render-pipelines.core@5.13.0\Runtime\Utilities\CoreUtils.cs:323)
UnityEngine.Experimental.Rendering.HDPipeline.HDRenderPipeline:.ctor(HDRenderPipelineAsset) (at C:\Users\Dan\Documents\GitHub\Gravia\Library\PackageCache\com.unity.render-pipelines.high-definition@5.13.0-preview\Runtime\RenderPipeline\HDRenderPipeline.cs:314)
UnityEngine.Experimental.Rendering.HDPipeline.HDRenderPipelineAsset:CreatePipeline() (at C:\Users\Dan\Documents\GitHub\Gravia\Library\PackageCache\com.unity.render-pipelines.high-definition@5.13.0-preview\Runtime\RenderPipeline\HDRenderPipelineAsset.cs:35)
UnityEngine.Rendering.RenderPipelineAsset:InternalCreatePipeline() (at C:\buildslave\unity\build\Runtime\Export\RenderPipeline\RenderPipelineAsset.cs:9)
UnityEngine.Rendering.RenderPipelineManagerrepareRenderPipeline(RenderPipelineAsset) (at C:\buildslave\unity\build\Runtime\Export\RenderPipeline\RenderPipelineManager.cs:84)
UnityEngine.Rendering.RenderPipelineManageroRenderLoop_Internal(RenderPipelineAsset, Camera[], IntPtr) (at C:\buildslave\unity\build\Runtime\Export\RenderPipeline\RenderPipelineManager.cs:57)

(Filename: C:/Users/Dan/Documents/GitHub/Gravia/Library/PackageCache/com.unity.render-pipelines.core@5.13.0/Runtime/Utilities/CoreUtils.cs Line: 323)

Cannot create required material because shader is null
UnityEngine.DebugLogHandler:Internal_Log(LogType, LogOption, String, Object)
UnityEngine.DebugLogHandler:LogFormat(LogType, Object, String, Object[])
UnityEngine.Logger:Log(LogType, Object)
UnityEngine.Debug:LogError(Object)
UnityEngine.Rendering.CoreUtils:CreateEngineMaterial(Shader) (at C:\Users\Dan\Documents\GitHub\Gravia\Library\PackageCache\com.unity.render-pipelines.core@5.13.0\Runtime\Utilities\CoreUtils.cs:323)
UnityEngine.Experimental.Rendering.HDPipeline.HDRenderPipeline:.ctor(HDRenderPipelineAsset) (at C:\Users\Dan\Documents\GitHub\Gravia\Library\PackageCache\com.unity.render-pipelines.high-definition@5.13.0-preview\Runtime\RenderPipeline\HDRenderPipeline.cs:315)
UnityEngine.Experimental.Rendering.HDPipeline.HDRenderPipelineAsset:CreatePipeline() (at C:\Users\Dan\Documents\GitHub\Gravia\Library\PackageCache\com.unity.render-pipelines.high-definition@5.13.0-preview\Runtime\RenderPipeline\HDRenderPipelineAsset.cs:35)
UnityEngine.Rendering.RenderPipelineAsset:InternalCreatePipeline() (at C:\buildslave\unity\build\Runtime\Export\RenderPipeline\RenderPipelineAsset.cs:9)
UnityEngine.Rendering.RenderPipelineManagerrepareRenderPipeline(RenderPipelineAsset) (at C:\buildslave\unity\build\Runtime\Export\RenderPipeline\RenderPipelineManager.cs:84)
UnityEngine.Rendering.RenderPipelineManageroRenderLoop_Internal(RenderPipelineAsset, Camera[], IntPtr) (at C:\buildslave\unity\build\Runtime\Export\RenderPipeline\RenderPipelineManager.cs:57)

(Filename: C:/Users/Dan/Documents/GitHub/Gravia/Library/PackageCache/com.unity.render-pipelines.core@5.13.0/Runtime/Utilities/CoreUtils.cs Line: 323)

NullReferenceException: Object reference not set to an instance of an object
at UnityEngine.Experimental.Rendering.HDPipeline.HDRenderPipeline.DownsampleDepthForLowResTransparency (UnityEngine.Experimental.Rendering.HDPipeline.HDCamera hdCamera, UnityEngine.Rendering.CommandBuffer cmd) [0x00097] in C:\Users\Dan\Documents\GitHub\Gravia\Library\PackageCache\com.unity.render-pipelines.high-definition@5.13.0-preview\Runtime\RenderPipeline\HDRenderPipeline.cs:3230
at UnityEngine.Experimental.Rendering.HDPipeline.HDRenderPipeline.ExecuteRenderRequest (UnityEngine.Experimental.Rendering.HDPipeline.HDRenderPipeline+RenderRequest renderRequest, UnityEngine.Rendering.ScriptableRenderContext renderContext, UnityEngine.Rendering.CommandBuffer cmd) [0x00f18] in C:\Users\Dan\Documents\GitHub\Gravia\Library\PackageCache\com.unity.render-pipelines.high-definition@5.13.0-preview\Runtime\RenderPipeline\HDRenderPipeline.cs:1924
at UnityEngine.Experimental.Rendering.HDPipeline.HDRenderPipeline.Render (UnityEngine.Rendering.ScriptableRenderContext renderContext, UnityEngine.Camera[] cameras) [0x00891] in C:\Users\Dan\Documents\GitHub\Gravia\Library\PackageCache\com.unity.render-pipelines.high-definition@5.13.0-preview\Runtime\RenderPipeline\HDRenderPipeline.cs:1423
at UnityEngine.Rendering.RenderPipeline.InternalRender (UnityEngine.Rendering.ScriptableRenderContext context, UnityEngine.Camera[] cameras) [0x00020] in C:\buildslave\unity\build\Runtime\Export\RenderPipeline\RenderPipeline.cs:72
at UnityEngine.Rendering.RenderPipelineManager.DoRenderLoop_Internal (UnityEngine.Rendering.RenderPipelineAsset pipe, UnityEngine.Camera[] cameras, System.IntPtr loopPtr) [0x00025] in C:\buildslave\unity\build\Runtime\Export\RenderPipeline\RenderPipelineManager.cs:67

(Filename: C:/Users/Dan/Documents/GitHub/Gravia/Library/PackageCache/com.unity.render-pipelines.high-definition@5.13.0-preview/Runtime/RenderPipeline/HDRenderPipeline.cs Line: 3230)

I tried adding the shader it's complaining about (HDRP/DownsampleDepth) to the list of shaders to always include, but it doesn't change the behavior.

This appears to cause the game to sit on the splash screen consuming 100% of one of the CPU cores, never getting past the splashscreen. Any ideas?

 

I haven't been able to resolve this yet. Things I've tried:

• Completely removing HDRP package and readding it.
• Creating a new HDRP Asset, in case there was an issue with the one I migrated from 4.x.

Depending on which scene I place first in my build, it either freezes on the splash screen, or it loads the scene but then spams the log file with a null reference exception at HDRenderPipeline.cs:3230.

Trying to set up a clean HDRP project to see if it happens there.

 

I think I see what's going on here, and I have a workaround, but this seems really weird/messed up.

Here's some diagnostics. It seems that HDRenderPipeline.cs create several materials via CoreUtils.CreateEngineMaterial. This was the case under 4.x, and with 5.x some additional materials were added. It seems that the crashes I'm experiencing are the result of some of those newer materials not instantiating due to the shader being null. I added some debug output, to print out the shaders and the value from the HDRP asset, and got this:

• Name: copyStencilBufferPS; Shader: Hidden/HDRP/CopyStencilBuffer
• Name: cameraMotionVectorsPS; Shader: Hidden/HDRP/CameraMotionVectors
• Name: decalNormalBufferPS; Shader: Hidden/HDRP/Material/Decal/DecalNormalBuffer
• Name: copyDepthBufferPS; Shader: Hidden/HDRP/CopyDepthBuffer
• Name: downsampleDepthPS; Shader: null
• Name: upsampleTransparentPS; Shader: null
• Name: applyDistortionPS; Shader: Hidden/HDRP/ApplyDistortion
• Name: debugViewMaterialGBufferPS; Shader: Hidden/HDRP/DebugViewMaterialGBuffer
• Name: debugViewMaterialGBufferPS; Shader: Hidden/HDRP/DebugViewMaterialGBuffer
• Name: debugDisplayLatlongPS; Shader: Hidden/HDRP/DebugDisplayLatlong
• Name: debugFullScreenPS; Shader: Hidden/HDRP/DebugFullScreen
• Name: debugColorPickerPS; Shader: Hidden/HDRP/DebugColorPicker
• Name: blitPS; Shader: Hidden/HDRP/Blit

You can see that downsampleDepthPS and upsampleTransparentPS are null. To be clear, this means that 'asset.renderPipelineResources.shaders.downsampleDepthPS' is null.

If I look at "HDRenderPipelineResources.asset" under \com.unity.render-pipelines.high-definition@5.13.0-preview\Runtime\RenderPipelineResources, I find that the asset doesn't have any content for "downsampleDepthPS" or "upsampleTransparentPS". It has entries for all the other shaders listed above, but not the two that are giving me trouble. Weirdly, if I select this file in Unity, I see it, and it contains the shaders:



But if I show the same file in a text editor, those two entries are missing:



So it's a total mystery to me how this file is showing something in the Inspector that isn't in the file itself. If I look on GitHub, I see that the 5.13 version of HDRenderPipelineResources.asset also doesn't contain the shaders:

https://github.com/Unity-Technologi...lineResources/HDRenderPipelineResources.asset

It seems they were only added 13 days ago:

https://github.com/Unity-Technologi...mmit/3e8c5df0d82a6ce158ab928f2f76f1ca79c96a65

But those properties are referenced by a commit back in March:

https://github.com/Unity-Technologi...mmit/2287b07b666c96d481260379ef2f2fcd63cc0b09

So I'm totally confused about how this is all working.

Anyway, my workaround was to create a copy of HDRenderPipelineResources.asset and add it to my Assets directory. Upon doing so, I can now see the two empty fields for downsampleDepthPS and upsampleTransparentPS, and I can assign the shaders to them. Now I can get passed those exceptions.

So what could be happening here? Why, when I click on HDRenderPipelineResources.asset, does the inspector show me that the asset has values for downsampleDepthPS and upsampleTransparentPS, even though those values aren't in the file? Why does the 5.13 version of HDRP have a dependency on those values being in the HDRenderPipelineResources, when those values were only just added?

 

@dgoyette ,
I got the same issue, thanks to your explanations I managed to fix it in a similar way than yours without losing too much hair !

Mine has been even stranger : it happened once after I had changed the default fullscreen mode from fullscreen window to exclusive, so I rebuilt the game, and it worked fine for a couple rebuilds ; then I switched back the default fullscreen mode, and then there was no way to get ride of the error anymore by rebuilding the game..!

 

This exact same issue occurred to me again, this time when updating my project from HDRP 7.3.1 to HDRP 7.4.1. This time, the HDRenderPipelineResources file appeared to show a reference to a shader for "Resolve Motion Vec PS":



However, if I make a copy of the HDRenderPipelineResources and drag it into my project, the editable version of this asset shows that the shader is null:



So, the Inspector is making it seem like this shader has a value assigned, but in reality it's null, and it results in an error being thrown by CoreUtils.CreateEngineMaterial().

If I look on the GitHub project for HDRenderPipelineResources.asset under tag 7.4.1, the file is missing an entry for "resolveMotionVecPS":

https://github.com/Unity-Technologi...lineResources/HDRenderPipelineResources.asset

And yet, HDRP is trying to make use of it in the HDRenderPipeline.cs constructor:

Code (CSharp):

1. m_MotionVectorResolve = CoreUtils.CreateEngineMaterial(asset.renderPipelineResources.shaders.resolveMotionVecPS);

 

This exact problem occurred once again after upgrading from 7.4.1 to 7.4.3.

If I look at the HDRP package, it claims to have a valid reference for Resolve Motion Vec PS:



However, if I make a copy of HDRPDefaultPipelineResources, such that it's not editable, that shader is showing up as empty:



So, once again, how is the inspector for the read-only version of this file showing a valid shader, even though the file itself doesn't have one? If I manually open the file and look at its contents, it doesn't have a value for "resolveMotionVecPS". Why is this missing from the file?

And if I look at this file on Github, for the 7.4.x branch, the file also doesn't contain a value for "resolveMotionVecPS":

https://github.com/Unity-Technologi...lineResources/HDRenderPipelineResources.asset

@SebLagarde , any chance you could lend some insight on why this shader is missing in 7.4.x? And why the inspector falsely claims it's not missing? It seems the only workaround for this is to download HDRP as a local package rather than using the package manager. I don't understand how this isn't affecting everyone.