Unity 贴图相关的shader

纹理与diffuse

• UV偏移

  f.uv = v.texcoord.xy * _MainTex_ST.xy  + _MainTex_ST.zw;
  

• texture

  fixed3 texColor = tex2D(_MainTex, f.uv.xy)*_Color.rgb;
  

Shader "Siki/11-Texture"{
    Properties{
        //_Diffuse("Diffuse Color",Color) = (1,1,1,1)
        _Color("Color",Color)=(1,1,1,1)
        _MainTex("Main Tex",2D) = "white"{}
        _Specular("Specular Color",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 _Diffuse;
            fixed4 _Color;
            sampler2D _MainTex;
            float4 _MainTex_ST; //固定写法 操作纹理的Scale Tranlate
            fixed4 _Specular;
            half _Gloss;
            
            struct a2v{
                float4 vertex:POSITION;
                float3 normal:NORMAL;
                float4 texcoord:TEXCOORD0;
            };
            struct v2f {
                float4 svPos:SV_POSITION;
                float3 worldNormal:TEXCOORD0;
                float4 worldVertex:TEXCOORD1;
                float2 uv:TEXCOORD2;
            };

            v2f vert(a2v v) {
                v2f f;
                f.svPos = UnityObjectToClipPos(v.vertex);
                f.worldNormal = UnityObjectToWorldNormal(v.normal);
                f.worldVertex = mul(v.vertex, unity_WorldToObject);
                f.uv = v.texcoord.xy * _MainTex_ST.xy  + _MainTex_ST.zw;
                return f;
            }
            fixed4 frag(v2f f) :SV_Target{
                fixed3 normalDir = normalize(f.worldNormal);
                fixed3 lightDir = normalize(WorldSpaceLightDir(f.worldVertex));
                fixed3 texColor = tex2D(_MainTex, f.uv.xy)*_Color.rgb;
                fixed3 diffuse = _LightColor0.rgb * texColor * max(dot(normalDir, lightDir), 0);
                fixed3 viewDir = normalize(UnityWorldSpaceViewDir(f.worldVertex));
                fixed3 halfDir = normalize(lightDir + viewDir);
                fixed3 specular = _LightColor0.rgb * _Specular.rgb * pow(max(dot(normalDir, halfDir), 0), _Gloss);
                fixed3 tempColor = diffuse + specular + UNITY_LIGHTMODEL_AMBIENT.rgb*texColor;
                return fixed4(tempColor, 1);
            }

            ENDCG
        }
    }
    Fallback "Specular"
}

纹理与NormalMap

• 切线空间

  TANGENT_SPACE_ROTATION;//调用这个后之后，会得到一个矩阵 rotation 这个矩阵用来把模型空间下的方向转换成切线空间下
  

• 得到模型空间下的平行光方向,

  //ObjSpaceLightDir(v.vertex)//
  f.lightDir = mul(rotation, ObjSpaceLightDir(v.vertex)); 
  

• 切线空间下的法线

  fixed3 tangentNormal = UnpackNormal(normalColor);
  

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

Shader "Siki/13-Rock Normal Map"{
    Properties{
        //_Diffuse("Diffuse Color",Color) = (1,1,1,1)
        _Color("Color",Color) = (1,1,1,1)
        _MainTex("Main Tex",2D) = "white"{}
        _NormalMap("Normal Map",2D) = "bump"{}
        _BumpScale("Bump Scale",Float)=1
    }
    SubShader{
        Pass{
            Tags{ "LightMode" = "ForwardBase" }
            CGPROGRAM
            #include "Lighting.cginc"
            #pragma vertex vert
            #pragma fragment frag

            //fixed4 _Diffuse;
            fixed4 _Color;
            sampler2D _MainTex;
            float4 _MainTex_ST;
            sampler2D _NormalMap;
            float4 _NormalMap_ST;
            float _BumpScale;

            struct a2v {
                float4 vertex:POSITION;
                float3 normal:NORMAL;
                float4 tangent:TANGENT;//tangent.w是用来确定切线空间中坐标轴的方向的 
                float4 texcoord:TEXCOORD0;
            };
            struct v2f {
                float4 svPos:SV_POSITION;
                //float3 worldNormal:TEXCOORD0;
                //float4 worldVertex:TEXCOORD1;
                float3 lightDir : TEXCOORD0;
                float4 uv:TEXCOORD1;
            };

            v2f vert(a2v v) {
                v2f f;
                f.svPos = UnityObjectToClipPos(v.vertex);
                //    f.worldNormal = UnityObjectToWorldNormal(v.normal);
                //    f.worldVertex = mul(v.vertex, _World2Object);
                f.uv.xy = v.texcoord.xy * _MainTex_ST.xy + _MainTex_ST.zw;
                f.uv.zw = v.texcoord.xy * _NormalMap_ST.xy + _NormalMap_ST.zw;
                TANGENT_SPACE_ROTATION;//调用这个后之后，会得到一个矩阵 rotation 这个矩阵用来把模型空间下的方向转换成切线空间下
                //ObjSpaceLightDir(v.vertex)//得到模型空间下的平行光方向 
                f.lightDir = mul(rotation, ObjSpaceLightDir(v.vertex)); 
                return f; 
            }
            fixed4 frag(v2f f) :SV_Target{
                //fixed3 normalDir = normalize(f.worldNormal);
                fixed4 normalColor = tex2D(_NormalMap,f.uv.zw);
                //    fixed3 tangentNormal = normalize(  normalColor.xyz * 2 - 1 ) ; //切线空间下的法线
                fixed3 tangentNormal = UnpackNormal(normalColor);
                tangentNormal.xy = tangentNormal.xy*_BumpScale;
                tangentNormal = normalize(tangentNormal);
                fixed3 lightDir = normalize(f.lightDir);
                fixed3 texColor = tex2D(_MainTex, f.uv.xy)*_Color.rgb;
                fixed3 diffuse = _LightColor0.rgb * texColor * max(dot(tangentNormal, lightDir), 0);
                fixed3 tempColor = diffuse + UNITY_LIGHTMODEL_AMBIENT.rgb*texColor;
                return fixed4(tempColor, 1);
            }
            ENDCG
        }    
    }
        Fallback "Specular"
}