Shader error: too many "TEXCOORD"

Unity Engine
1

I wrote a surface shader that’s an extension to the bumped diffuse shader (adds snow based on world normal). that worked, then I made a variant with specular, but that doesn’t compile. I get the error:
Shader error in ‘Custom/snowBumpedSpec’: Program ‘frag_surf’, input semantic attribute “TEXCOORD” has too big of a numeric index (8) at line 74 Keywords: DIRECTIONAL, LIGHTMAP_OFF, DIRLIGHTMAP_OFF, SHADOWS_SCREEN

So apparently I use to many texcoord, which doesn’t make much sense to me, as I don’t use more than in my (snow) bumped diffuse shader.

Also, I looked at the built in Reflective/Bumped Specular shader, and it’s just as complex; the same amount of textures, the same amount of parameters, and even 1 more uv-set (I use the float2 uv_MainTex for both the diffuse and normalmap)

So anyone that can help me ?

here’s the setup of the shader:

Shader "Custom/snowBumpedSpec" 
{
    Properties 
    {
		_MainColor ("Color", Color) = (1,1,1,1)
		_MainTex ("Texture", 2D) = "white" {}
		_SpecColor ("Specular Color", Color) = (0.5,0.5,0.5,1)
		_Shininess ("Shininess", Range (0.01, 1)) = 0.078125
		_BumpMap ("Bumpmap", 2D) = "bump" {}
		_SnowTex ("Snow", 2D) = "white" {}
		_SnowAmount ("Snow Amount", Range(0.0,5.0)) = 1.0
    }
    
    SubShader 
    {
      Tags { "RenderType" = "Opaque" }
      
      CGPROGRAM
		#pragma exclude_renderers gles
      #pragma surface surf BlinnPhong nolightmap nodirlightmap
      #pragma target 3.0
      
      struct Input 
      {
          float2 uv_MainTex;//:TEXCOORD0;
          //float2 uv_BumpMap;
          float3 worldPos;
          float3 worldNormal;
			INTERNAL_DATA
      };
      
      float4 _MainColor;
      sampler2D _MainTex;
		float _Shininess;
      sampler2D _BumpMap;
      sampler2D _SnowTex;
      float _SnowAmount;
      
		void surf (Input IN, inout SurfaceOutput o) 
		{
	      	float4 tex = tex2D (_MainTex, IN.uv_MainTex)*_MainColor;
	      	float4 snow = tex2D (_SnowTex, IN.worldPos.xz);
          	o.Normal = UnpackNormal (tex2D (_BumpMap, IN.uv_MainTex));
          	
			float snowfactor = 1 - WorldNormalVector(IN, normalize(o.Normal)).y;
			snowfactor = snow.a - snowfactor;
			
			if (_SnowAmount>1)
				snowfactor *= _SnowAmount;
			else
				snowfactor += (_SnowAmount-1)*2;
			snowfactor = saturate(snowfactor);
			tex = snow*snowfactor + tex*(1-snowfactor);
			o.Albedo = tex.rgb;
			o.Specular = _Shininess;
			o.Gloss = tex.a;
			o.Alpha = tex.a;
		}
      ENDCG
    } 
    
    Fallback "snowSpecular"
  }
2

You also use world position world normal, and those need to be passed in the texture coordinate interpolators.

Things you can do:

  1. use shader model 3.0 (#pragma target 3.0), that has two more texture interpolators.
  2. disable stuff that you don’t need from the shader. Don’t need lightmaps? Add “nolightmap” to #pragma surface line. Don’t need directional lightmaps? Add “nodirlightmap” and so on.
  3. do you actually use world position? If not, do not put it into the Input struct.
3
  1. I already use #pragma target 3.0
  2. I added nolightmap and nodirlightmap, but that doesn’t seem to make any difference, still “too big of a numeric index (8)”, are there other things I can disable that might help ?
  3. I do use the world position, I use it for the uv’s for the snow. But I don’t really use the worldNormal directly, I mean I use the normal map to set the normal, then I use WorldNormalVector() to get the worldnormal, I didn’t seem to work any other way, is that the correct way of dooing this ?

thanks for the reply Aras

4

Well, I guess then we have to see your full shader to tell any more details.

5

alright, I’ve editted my first post and added the full shader there.

6

Sorry, didn’t have time to look into this earlier, vacations stuff…

Turns out the culprit is OpenGL here; by default we compile into OpenGL ARB vertex/fragment programs, even in SM3.0 mode (long story of driver bugs with GLSL etc.). If you tell Unity to compile into GLSL when targetting OpenGL, the shader works.

Just add “#pragma glsl” line somewhere in your CGPROGRAM block.