Surface Shader with StructuredBuffer Error [SOLVED]

Unity Engine
1

Hi,

How can I use Surface Shader with StructuredBuffer input?

Shader "Custom/DirectX 11 Diffuse Mapping" {
   Properties
    {
        _MainTex ("Texture", 2D) = "white" {}
    }
     SubShader {
         Tags {"LightMode" = "ForwardBase" }
            
              
         Pass {
         CGPROGRAM
         #include "UnityCG.cginc"
         #pragma target 5.0
         #pragma vertex vertex_shader
         #pragma surface surf Lambert vertex:vert
    
         sampler2D _MainTex;
         float4 _MainTex_ST;
         uniform fixed4 _LightColor0;
            
         struct Point{
             float3         vertex;
             float3         normal;
             float4         tangent;
             float2 uv;
         };   
         StructuredBuffer<Point> points;

         struct v2f {
            float4 pos : SV_POSITION;
            float4 col : COLOR;
            float2 uv : TEXCOORD0;
         };
         v2f vertex_shader (uint id : SV_VertexID, uint inst : SV_InstanceID) {
            float4 vertex_position =  float4(points[id].vertex,1.0f);
            float4 vertex_normal = float4(points[id].normal, 1.0f);         
            v2f o;
            // . . .
            return o;
         }
   
         struct Input {
            float4 color : COLOR;
         };
         void surf (Input IN, inout SurfaceOutput o) {
             o.Albedo = 1; // 1 = (1,1,1,1) = white
         }

         ENDCG
     }
     }
}

When I’m trying to get vertices in vertex shader and then use surface shader - it doesn’t work.
Its saying

Shader error in '...': Unexpected identifier "StructuredBuffer". Expected one of: typedef const void inline uniform nointerpolation extern shared static volatile row_major column_major struct or a user-defined type at line 31
2

Ok, I fixed this error (found a solution here) but still can’t make StructuredBuffer work with SurfaceShader

Here’s new code. I added SHADER_API_D3D11 to fix the problem

Shader "Custom/kek" {

   Properties {
      _MainTex ("Texture", 2D) = "white" {}
   }

   SubShader {

      Tags { "RenderType" = "Opaque" }            
           

      CGPROGRAM

      // #include "UnityCG.cginc"
      #pragma target 5.0
      #pragma vertex vert
      #pragma surface surf Lambert
 
      sampler2D _MainTex;
      float4 _MainTex_ST;
         
      struct Point{
         float3 vertex;
         float3 normal;
         float4 tangent;
         float2 uv;
      };   


      #ifdef SHADER_API_D3D11
         StructuredBuffer<Point> points;
      #endif

      struct v2f {
         float4 pos : SV_POSITION;
         float4 col : COLOR;
         float2 uv : TEXCOORD0;
      };

      v2f vert (uint id : SV_VertexID) { //, uint inst : SV_InstanceID

         float4 vertex_position =  float4(points[id].vertex,1.0f);
         float4 vertex_normal = float4(points[id].normal, 1.0f);      
         v2f o;
         //....
         return o;
      }

      struct Input {
          float4 color : COLOR;
      };
      void surf (Input IN, inout SurfaceOutput o) {
         o.Albedo = fixed4(1f,0f,0f,1f);
      }

      ENDCG

   }
}

The problem now is that StructuredBuffer needs
uint id : SV_VertexID as vertex shader input
but SurfaceShader needs
inout appdata_full v as vertex shader input

So I have this conflict and error message

Shader error in '...': Surface shader vertex function 'vert' #0 parameter has wrong modifier; has no modifier but needs 'inout' at 'uint id' at line 12

How can I solve it ?

3

appdata_full is just one of the helper input structs. You can define your own.

4

ok, but how can i combine uint id : SV_VertexID with appdata_custom?
what’s the right way to define vertex shader params? that I have SV_VertexID as an input and appdata_custom as an output?

5

Well, you can combine it by making that uint part of the struct. I honestly don’t know whether it will work, but that would be the first thing to try. The input and output of a vertex and fragment shader is commonly a combination of values combined into a struct. So, just add the uint to the input struct.

6

Just tried it. Didn’t work

Shader "Custom/kek"{ //StructuredBuffer+SurfaceShader

   // Properties {}
   SubShader {

         CGPROGRAM
  
         #include "UnityCG.cginc"
         #pragma target 5.0
         #pragma surface surf Lambert vertex:vert

         struct Point{
            float3 vertex;
            float3 normal;
            float4 tangent;
            float2 uv;
         };     

         #ifdef SHADER_API_D3D11
            StructuredBuffer<Point> points;
         #endif


         struct appdata{
            float4 vertex : SV_POSITION;
            float3 normal : NORMAL;
            float4 texcoord : TEXCOORD0;

            uint id : SV_VertexID;
            uint inst : SV_InstanceID;
         };

         struct Input {
            float4 color : COLOR;
         };

         void vert (inout appdata v) {

            v.vertex =  float4(points[id].vertex,1.0f);
            v.normal =  float4(normalize(points[id].normal), 1.0f);
            v.texcoord = points[id].uv;

         }


         void surf (Input IN, inout SurfaceOutput o) {
            o.Albedo = fixed4(1f,0f,0f,1f);
         }

         ENDCG

   }
}

Now it’s giving me this error

Shader error in '...': undeclared identifier 'id' at line 39 (on d3d11)

So, obviously id isn’t set. Please, unity people, help!

7

Because it’s part of the appdata struct, which is being passed to the vert function via the v variable.

points[v.id]

4 Likes
8

yeah! now it works.
dude u always appear out of nowhere and fix stuff. unity wizard. thank you.

1 Like