When did editor shader compilation start taking forever and how to speed it up?

News & General Discussion
1

I used to love working on shaders because unless you had a ton of includes, compilation was lightning fast. Recently noticed that any shader tweek now takes forever to compile and unity grinds to a halt while doing so.

What happened and is there any way to speed this up?

2

If this is during building, often unticking “optimize mesh data” (in player settings) can improve times by up to 95%. Enterprise project we had went from 2 hours build time to 5 minutes with that alone :wink: (As in if its shader compilation in the build that is taking ages, which usually is the main thing taking up time during building)

If in editor without building, I have no idea but I have not noticed this on any versions I am using (including the beta)

3

I’m talking about editing shaders and the internal editor compilation step when you save the shader. You haven’t noticed any slowdown compared to a few years ago??

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4

So for example. I open a shader file. Paste in a super simple example from the manual:

Shader "Custom/TextureCoordinates/ChessOpt" {
   SubShader {
       Pass {
           CGPROGRAM
           #pragma vertex vert_img
           #pragma fragment frag

           #include "UnityCG.cginc"

           fixed4 frag(v2f_img i) : SV_Target {
               bool p = fmod(i.uv.x*8.0,2.0) < 1.0;
               bool q = fmod(i.uv.y*8.0,2.0) > 1.0;
              
               return fixed4(fixed3((p && q) || !(p || q)),1.0);
           }
           ENDCG
       }
   }
}

It takes 39 seconds for unity to compile this! What happened? It used to be like a half second!

5

No not noticing that on my side, I suggest you file a bug report!

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6

What Unity version?

7

This is 2019.4.23f1 - maybe I should update?

Is this really not a thing for others?

8

Try deleting \library and re-importing the project. That seemed to solve it for me last time I ran into it.

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9

I’ll try that tonight, thanks for the tip.

10

If your Library/ShaderCache.db file is “fairly huge” then you might be affected by this bug https://issuetracker.unity3d.com/issues/shader-error-db-grows-on-each-build – workaround is to either delete Library/ShaderCache.db once/if it grows large, or for Unity 2019 versions, to update to 2019.4.29 where it’s fixed (release notes).

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