SPR batcher on hand-written shader / URP

This is a fixed funtion shader, which currently will generate a Builtin shader rather than a URP shader (if you select the shader and look at the inspector for it, you can compile the 'Fixed Function' code, and you will see why it will not work with URP).
The reason it will render is because URP was designed so that it could render built in shaders that were unlit. But this is not the way to go forward, and you will need to write a shader using the new SRP shaderlibrary, unfortunately we are super slim when it comes to learning resources here.

If you want to make a custom URP shader take a good look at the provided ones in URP, they are more complicated than they need to be due to the 'uber' nature of them and also platform support, XR, instancing, etc.

Below you can see a very basic Unlit shader in URP, this is what I would say is probably the bare minimum.

Code (CSharp):

1. Shader "Unlit/NewUnlitShader"
2. {
3.     Properties
4.     {
5.         _Color("Color", Color) = (1,1,1,1)
6.     }
7.     SubShader
8.     {
9.         Tags { "RenderType"="Opaque" }
10.      
11.         Pass
12.         {
13.             HLSLPROGRAM
14.             // Required to compile gles 2.0 with standard srp library
15.             #pragma prefer_hlslcc gles
16.             #pragma exclude_renderers d3d11_9x
17.             // Will make life easier to have at least URP core.hlsl
18.             #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Core.hlsl"
19.  
20.             #pragma vertex vert
21.             #pragma fragment frag
22.  
23.             // For SRP Batcher to work you need to put things in the right Cbuffer
24.             CBUFFER_START(UnityPerMaterial)
25.             half4 _Color;
26.             CBUFFER_END
27.  
28.             float4 vert(float4 positionOS : POSITION) : SV_POSITION
29.             {
30.                 // This struct contains commonly used transformations such as Clip, World, etc
31.                 VertexPositionInputs vertexInput = GetVertexPositionInputs(positionOS.xyz);
32.                 return vertexInput.positionCS;
33.             }
34.  
35.             half4 frag() : SV_Target
36.             {
37.                 return _Color;
38.             }
39.             ENDHLSL
40.         }
41.     }
42. }
43.  

To that note, you will notice this is a vert/frag shader and these are the only shaders fully supoported under SRP, the other optiuon is shadergraph, these will also generate shader that have full platform support, XR, instancing etc.

This shader should work on all platforms but will not work with intancing or stereo rendering.

more information about the SRP batcher(including custom shaders):https://blogs.unity3d.com/2019/02/28/srp-batcher-speed-up-your-rendering/

 

If they are properties you plan to have different on different materials then yes, if it's properties that will be different per renderer then you need UnityPerDraw cbuffer, if it is a constant amongst all things that use this shader then they can live ouside of a cbuffer. Again check this blogpost out as it has a section about writing your own shaders: https://blogs.unity3d.com/2019/02/2...4.1974275149.1584002334-1241191896.1583834030