Shader 法线贴图参考代码

// Upgrade NOTE: replaced 'mul(UNITY_MATRIX_MVP,*)' with 'UnityObjectToClipPos(*)'

Shader "wacky/s10 shader bump"{
    Properties{
    _Color("Color Tint",Color) = (1,1,1,1)
    _MainTex("Main Tex",2D) = "white"{}
    _BumpMap("Bump Map",2D) = "bump"{}
    _BumpScale("Bump Scale",Float) = 1.0
    _Specular ("Specular",Color) = (1,1,1,1)
    _Gloss ("Gloss",Range(10,200)) = 20
    }

    SubShader{
        Pass{
        Tags {"LightMode" = "ForwardBase"}
        CGPROGRAM
#include "Lighting.cginc"
#pragma vertex vert
#pragma fragment frag
        fixed4 _Color;
        sampler2D _MainTex;
        float4 _MainTex_ST;
        sampler2D _BumpMap;
        float4 _BumpMap_ST;
float _BumpScale;
        fixed4 _Specular;
float _Gloss;

        struct a2v{
            float4 vertex:POSITION;
            float3 normal:NORMAL;
            float4 tangent:TANGENT;//切线向量
            float4 texcoord:TEXCOORD;//贴图的位置信息
        };

        struct v2f{
            float4 pos:SV_POSITION;
            float4 uv:TEXCOORD0;
            float3 lightDir:TEXOOCRD1;
            float3 viewDir:TEXCOORD2;
            };

        v2f vert(a2v v){
            v2f f;
            f.pos = UnityObjectToClipPos(v.vertex);
            f.uv.xy=v.texcoord.xy * _MainTex_ST.xy + _MainTex_ST.zw; //uv.xy存储贴图纹理坐标
            f.uv.zw = v.texcoord.xy * _BumpMap_ST.xy + _BumpMap_ST.zw;//uv.zw存储法线贴图纹理坐标
            TANGENT_SPACE_ROTATION; //内置宏 得到rotation变换矩阵 用以将模型切换到切线空间
            f.lightDir = mul(rotation,ObjSpaceLightDir(v.vertex)).xyz;
            f.viewDir = mul(rotation,ObjSpaceViewDir(v.vertex)).xyz;
return f;
        }

        fixed4 frag(v2f f):SV_Target{
            fixed3 tangentLightDir = normalize(f.lightDir);
            fixed3 tangentViewDir = normalize(f.viewDir);
            fixed4 packedNormal = tex2D(_BumpMap,f.uv.zw);
            fixed3 tangentNormal = UnpackNormal(packedNormal);
            tangentNormal.xy *= _BumpScale;
            tangentNormal.z = sqrt(1.0-saturate(dot(tangentNormal.xy,tangentNormal.xy)));
            fixed3 albedo = tex2D(_MainTex,f.uv).rgb * _Color.rgb;
            fixed3 ambient = UNITY_LIGHTMODEL_AMBIENT.xyz * albedo;
            fixed3 diffuse = _LightColor0.rgb * albedo * max(0,dot(tangentNormal,tangentLightDir));
            fixed3 halfDir = normalize(tangentLightDir + tangentViewDir);
            fixed3 specular = _LightColor0.rgb * _Specular.rgb * pow(max(0,dot(tangentNormal,halfDir)),_Gloss);
return fixed4(ambient + diffuse + specular,1.0); 
        }
        ENDCG
      }
    }
    Fallback "Diffuse"
}