Modify custom shader to add bump and normal maps

Question

I loathe to ask a "please do it for me" but I'm really stumped here. Shaders are a complete mystery and CG just baffles me.

I found this shader elsewhere on the internet. It makes sure an object's (like a wall) textures are set to world coordinates rather than object coordinates, so that I can place proceduraly generated objects and not worry about their textures matching. And it works like a charm. Now I would like to add normal and bump maps to it. I tried following unity's documentation on the subject, but I just get a ton of errors I can't even begin to comprehend. Here is the current shader text, the comments are me trying to add in a bump map. Help?

 Shader "Custom/World UV" 
 {
     Properties 
     {
         _Color ("Main Color", Color) = (1,1,1,1)
         _MainTex ("Texture (RGB)", 2D) = "surface" {} 
         //_BumpMap ("Bumpmap", 2D) = "bump" {}
         _Scale ("Texture Scale", Float) = 0.1
 
     }
 
     SubShader 
     {
         Tags { "RenderType"="Opaque" }
         
         CGPROGRAM
         #pragma surface surf Lambert
         
         struct Input 
         {
             float3 worldNormal;
             float3 worldPos;
         };
         
         sampler2D _MainTex;
         //sampler2D _BumpMap;
         float4 _Color;
         float _Scale;
 
         
         void surf (Input IN, inout SurfaceOutput o) 
         {
             float2 UV;
             fixed4 c;
             //fixed4 d;
             
             if(abs(IN.worldNormal.x)>0.5) 
             {
                 UV = IN.worldPos.yz; // side
                 c = tex2D(_MainTex, UV* _Scale);
                 //d = tex2D(_BumpMap, UV* _Scale);
             } 
             else if(abs(IN.worldNormal.z)>0.5) 
             {
                 UV = IN.worldPos.xy; // front
                 c = tex2D(_MainTex, UV* _Scale);
                 //d = tex2D(_BumpMap, UV* _Scale);
             } 
             else 
             {
                 UV = IN.worldPos.xz; // top
                 c = tex2D(_MainTex, UV* _Scale);
                 //d = tex2D(_BumpMap, UV* _Scale);
             }
             
             o.Albedo = c.rgb * _Color;
             //o.Normal = UnpackNormal (d);
         }
         ENDCG
     } 
     Fallback "VertexLit"
 }

Answer 1

First of all, I would move

c = tex2D(_MainTex, UV* _Scale); d = tex2D(_BumpMap, UV* _Scale);

outside of the branching if statement, since it does not change. Second of all, you've got what looks like an NVidia Cg shader in the middle of your unity shader, so you really can't fault the unity crew for not debugging for you. Best to stick to Unity's ShaderLab language. Fewer moving parts. Especially if you're not using an NVidia card. I'm not sure how Unity handles the conversion, but I'm positive that their language will be best for cross-platform consistency.

As for your actual code, normal maps are usually done using tangent space, which you're not computing here. But that won't keep your results from compiling; just from looking good. I haven't used Cg myself, but it seems pretty similar to glsl. I would get rid of those warnings first. On line 56, try changing c.rgb to c.rgba. Also, make sure you've got a properly encoded image file for your bumpmap loaded into the editor. Finally, notice that cg shaders in unity utilize half3 and half4 data types. I haven't done the research, so I'm not sure where to use these, but maybe you should.

Sorry I can't be more helpful, but I don't see anything else wrong with your code (except that I don't know where UnpackNormal came from), so perhaps you could try an NVidia forum for more help, or try rewriting in ShaderLab.

Answer 2

Answer by mavv · Aug 06, 2019 at 10:22 AM

Anyone figured it out? :)

Add comment · Share

Modify custom shader to add bump and normal maps

2 Replies

Your answer

Follow this Question

Related Questions