Resolved Compile error in shader in Unity 2020.2.3 but not in Unity 2019.2.17

I've written a few shaders which were working perfectly with Unity 2019.2.17.
When I upgrade to Unity 2020.2.3 they throw some errors and a lot of warnings.

The errors and warnings made no real sense, and in the end I've fixed one warning which fixed all the other warnings and errors.
It was this warning:

It was located on that line of code (please look at the right end of the line, the problem lies there...):

Code (CSharp):

1. // ************************************************************************************************************************************************ \\

Yes, I know that it's only a comment (I use that in a pattern to separate functions) and that it should work perfectly fine, yet it generates a warning.

I had hundreds of these warnings, and they generated other warnings and errors (I guess that at some point Unity simply stopped reading the code).

The fix was to replace my pattern with:

Code (CSharp):

1. // ************************************************************************************************************************************************

 

Thank you for the explanation.

You may want to change the error message, as it doesn't explain that at all:

 

No, my code had no space character between the last '\' and the new line.
It probably doesn't like the CR-LF and consider that CR is a space character.

Now that I know that '\\' is used to append the next line I won't have any problem with it again, but other people may face the same warning and struggle to find out the root of the problem.

 

Correct preprocessor behavior is great, but like Gladyon says, now I'm having this problem and I have no clue what to do with it.

 

@aleksandrk

I get this warning in the Console constantly that keeps polluting the logs:

>Shader warning in '[BrickBreak_vfx] [Burst] OutputUpdate': Extra space between '\' and newline. at VFXCommon.hlsl(204)

When I click the generated file it points to, the inspector says this:
>[Brick Break_vfx] [Burst] Output Update (Compute Shader)
>CSMain Directo3D11
>Preprocess only [false]
>Errors (6)
>Extra space between '\' and newline. ...................................................... 26 VFXCommon.hlsl:202
>Extra space between '\' and newline. at kernel CS Main ........................ 26 VFXCommon.hlsl:202
>Extra space between '\' and newline. ...................................................... 26 VFXCommon.hlsl:203
>Extra space between '\' and newline. at kernel CS Main ........................ 26 VFXCommon.hlsl:203
>Extra space between '\' and newline. ...................................................... 26 VFXCommon.hlsl:204
>Extra space between '\' and newline. at kernel CS Main ........................ 26 VFXCommon.hlsl:204

When I click "Show compiled code" and go to line 26 it says:
> 25: if_nz r0.y
> 26: ..ishl r0.y, r1.x, l(8)
> 27: ..ld_raw_indexable(raw_buffer)(mixed,mixed,mixed,mixed) r0.yzw, r0.y, t0.xxyz

(Added periods to show indent)

There's no '\' anywhere. This is a project that I've upgraded from a previous version to version 2021/2022. I've also recompiled all of my VFX Graph scripts but it keeps happening. I'm now using 2022.2.18.

 

Ah, duh, it didn't occur to me that VFXCommon.hlsl would be its own file. I found it under "Library/PackageCache/com.unity.render-pipelines.universal@14.0.7/Runtime/VFXGraph/Shaders/VFXCommon.hlsl"

Code (CSharp):

1. #if defined(_GBUFFER_NORMALS_OCT)
2. #define VFXComputePixelOutputToNormalBuffer(i,normalWS,uvData,outNormalBuffer) \
3. { \
4.     float2 octNormalWS = PackNormalOctQuadEncode(normalWS); \          // values between [-1, +1], must use fp32 on some platforms
5.     float2 remappedOctNormalWS = saturate(octNormalWS * 0.5 + 0.5); \  // values between [ 0,  1]
6.     half3 packedNormalWS = PackFloat2To888(remappedOctNormalWS); \     // values between [ 0,  1]
7.     outNormalBuffer = float4(packedNormalWS, 0.0); \
8. }
9. #else
10. #define VFXComputePixelOutputToNormalBuffer(i,normalWS,uvData,outNormalBuffer) \
11. { \
12.     outNormalBuffer = float4(normalWS, 0.0); \
13. }
14. #endif

I edited the file but Unity keeps regenerating the file as-is. I also reinstalled the com.unity.render-pipelines.universal@14.0.7 package but it keeps happening (and broke all my Shader Graph materials in the process ). I wonder if it's something else on my end?

 

Will look into it, thank you so much!

 

I can also confirm this is happening. It's just a warning, but it is annoying.

It started happening to me after I've updated the URP package from:
- "com.unity.render-pipelines.universal": "12.1.10",
+ "com.unity.render-pipelines.universal": "14.0.7",

 

Same here, same update of the `Visual Effect Graph` (and URP) package to 14.0.7.

 

Same issue.

Outside of the already-identified problem in the source with the " \" in the last lines of VFX Common in com.unity.render-pipelines.universal@14.0.7, when changing the Output Quad settings you can find that the Additive and Opaque mixing options don't trigger the warnings while Alpha and Alpha Premultiplied do.

I guess you could change to Additive and modify the colors a bit in certain use cases, if the warnings are the greater evil.

 

Same issue here...with update to Unity LTS 2022.3.0 (and hence Shader Graph 14.0.7)....

 

same issue on 2022.2.20f1 and visual effect graph 14.0.7

 

Looks like someone filed a bug for it some time ago.

https://issuetracker.unity3d.com/is...ine-warning-is-thrown-when-creating-a-new-vfx

 

I managed to get rid of the warnings locally, as a temporary solution, by removing the comments in the package manager. UnityHub\2022.3.0f1\Editor\Data\Resources\PackageManager\BuiltInPackages\com.unity.render-pipelines.universal\Runtime\VFXGraph\Shaders\VFXCommon.hlsl

#if defined(_GBUFFER_NORMALS_OCT)

#define VFXComputePixelOutputToNormalBuffer(i,normalWS,uvData,outNormalBuffer)\

{\

    float2 octNormalWS = PackNormalOctQuadEncode(normalWS);\

    float2 remappedOctNormalWS = saturate(octNormalWS * 0.5 + 0.5);\

    half3 packedNormalWS = PackFloat2To888(remappedOctNormalWS);\

    outNormalBuffer = float4(packedNormalWS, 0.0);\

}

#else

#define VFXComputePixelOutputToNormalBuffer(i,normalWS,uvData,outNormalBuffer)\

{\

    outNormalBuffer = float4(normalWS, 0.0);\

}

#endif

 

I can also confirm that I have the exact same issue within

Unity 2022.2.21f1

using

Shader Graph 14.0.7

and that the solution provided by @OliverTheLove (removing the comments at line 203, 204 and 205) worked fine to temporarily fix the problem.

 

I had that exact same issue with Unity 2022.2.21f1 and even after updating to 2022.3.1f1(lts) I still have that issue...
Shader Graph, Visual Effect Graph and URP 14.0.8

 

The issue still exists in the latest LTS 2022.3.2f1.

 

I wonder what LTS stands for. Definitely not long-term support for Unity Inc.

 

Bug exist at 2022.3.3f1

 

I have the same warning in 2022.3.0f1. I couldn't find any solution yet.

 

Confirming it is not fixed in 2023.1.3f1...still breaking "hidden" shaders.