地形混合shader

1.四个贴图混合

 Shader "Custom/BlendTex_surface" {
     Properties {
         _RTexture("Red Channel Texture", 2D) = "" {}
         _GTexture("Green Channel Texture", 2D) = "" {}
         _BTexture("Blue Channel Texture", 2D) = "" {}
         _ATexture("Alpha Channel Texture", 2D) = "" {}
         _Mask("Mask(RG)",2D) = ""{}
     }
     SubShader {
         Tags { "RenderType"="Opaque" }
         LOD 

         CGPROGRAM
         #pragma surface surf Lambert
         #pragma target 4.0

         sampler2D _RTexture;
         sampler2D _GTexture;
         sampler2D _BTexture;
         sampler2D _ATexture;

         sampler2D _Mask;

         struct Input {
             float2 uv_RTexture;
             float2 uv_GTexture;
             float2 uv_BTexture;
             float2 uv_ATexture;
             float2 uv_Mask;
         };

         void surf (Input IN, inout SurfaceOutput o) {
             float4 rTexData = tex2D(_RTexture, IN.uv_RTexture);
             float4 gTexData = tex2D(_GTexture, IN.uv_GTexture);
             float4 bTexData = tex2D(_BTexture, IN.uv_BTexture);
             float4 aTexData = tex2D(_ATexture, IN.uv_ATexture);
             float4 blendData = tex2D(_Mask, IN.uv_Mask);

             float4 finalColor;
             //根据blendData.g 将 RTexture 和 GTexture 混合
             finalColor = lerp(rTexData, gTexData, blendData.g);//原本为g
             //根据blendData.b 将 BTexture 混合
             finalColor = lerp(finalColor, bTexData, blendData.b);//原本为b
             //根据blendData.a 将 ATexture 混合
             finalColor = lerp(finalColor, aTexData , blendData.a);//原本为a
             finalColor = saturate(finalColor);
             o.Albedo = finalColor.rgb;
             o.Alpha = finalColor.a;
         }
         ENDCG
     }
     FallBack "Diffuse"
 }

BlendTex_surface

 Shader "Custom/BlendTex_vertfrag"
 {
 Properties
 {
     Tex0 ("Layer 0 (R)", 2D) = "white" {}
     Tex1 ("Layer 1 (G)", 2D) = "white" {}
     Tex2 ("Layer 2 (G)", 2D) = "white" {}
     Tex3 ("Layer 3 (A)", 2D) = "white" {}
     _Control ("Control (RGBA)", 2D) = "red" {}
     _IllumFactor ("Illumin Factor", Range(,)) =
 }

 SubShader
 {
     Tags{ "Queue" = "Geometry+110"   }
     Pass
     {

         Tags{"LightMode" = "ForwardBase" }

         CGPROGRAM
             #pragma vertex vert
             #pragma fragment frag
             #pragma target 2.0
             #include "UnityCG.cginc"

             sampler2D _Control;
             sampler2D Tex0;
             sampler2D Tex1;
             sampler2D Tex2;
             sampler2D Tex3;
             half _IllumFactor;

             half4 Tex0_ST;
             half4 Tex1_ST;
             half4 Tex2_ST;
             half4 Tex3_ST;
             half4 _Control_ST;

             struct v2f
             {
                 float4    pos : SV_POSITION;
                 half2  uv_Tex0:TEXCOORD0;
                 half2  uv_Tex1:TEXCOORD1;
                 half2  uv_Tex2:TEXCOORD2;
                 half2  uv_Tex3:TEXCOORD3;
                 half2  uv_Control:TEXCOORD4;
             }; 

             struct appdata
             {
                 float4 vertex : POSITION;
                 float4 texcoord : TEXCOORD0;
             };

             v2f vert (appdata v)
             {
                 float4 worldPos = mul(unity_ObjectToWorld, v.vertex);

                 v2f o;

                 o.uv_Control = v.texcoord.xy;
                 o.uv_Tex0 = TRANSFORM_TEX(v.texcoord ,Tex0);
                 o.uv_Tex1 = TRANSFORM_TEX(v.texcoord ,Tex1);
                 o.uv_Tex2 = TRANSFORM_TEX(v.texcoord, Tex2);
                 o.uv_Tex3 = TRANSFORM_TEX(v.texcoord, Tex3);
                 o.pos =  mul(UNITY_MATRIX_MVP, float4(v.vertex.xyz, ));

                 return o;
             }

             fixed4 frag(v2f i) : COLOR
             {
                 fixed4 splat_control = tex2D (_Control, i.uv_Control.xy);

                 fixed4 albedo = fixed4(,,,);
                 fixed4 Tex0Color = tex2D(Tex0, i.uv_Tex0);
                 //albedo.rgb  = splat_control.r * Tex0Color.rgb;...用这个会出现不明黑色阴影
                 fixed4 Tex1Color = tex2D(Tex1, i.uv_Tex1);
                 //albedo.rgb += splat_control.g * Tex1Color.rgb;

                 fixed4 Tex2Color = tex2D(Tex2, i.uv_Tex2).rgba;
                 //albedo.rgb += splat_control.b * Tex2Color;
                 fixed4 Tex3Color = tex2D(Tex3, i.uv_Tex3).rgba;
                 //albedo.rgb += splat_control.a * Tex3Color;

                 albedo = lerp(Tex0Color,Tex1Color, splat_control.g);
                 albedo = lerp(albedo,Tex2Color, splat_control.b);
                 albedo = lerp(albedo,Tex3Color, splat_control.a);

                 return albedo* _IllumFactor;
             }

         ENDCG
     }
 }
     FallBack "Diffuse"
 }

BlendTex_vertfrag

2.四个贴图（加法线）混合

 Shader "Custom/BlendNormalTex_surface" {
     Properties {
         _RTexture("Red Channel Texture", 2D) = "" {}
         _GTexture("Green Channel Texture", 2D) = "" {}
         _BTexture("Blue Channel Texture", 2D) = "" {}
         _ATexture("Alpha Channel Texture", 2D) = "" {}

         _RNormalTex ("RNormal Map", 2D) = "bump" {}
         _GNormalTex ("GNormal Map", 2D) = "bump" {}
         _BNormalTex ("BNormal Map", 2D) = "bump" {}
         _ANormalTex ("ANormal Map", 2D) = "bump" {}

         _RNormalIntensity ("RNormal Map Intensity", Range(-,)) =
         _GNormalIntensity ("GNormal Map Intensity", Range(-,)) =
         _BNormalIntensity ("BNormal Map Intensity", Range(-,)) =
         _ANormalIntensity ("ANormal Map Intensity", Range(-,)) =
         _IllumFactor ("Illumin Factor", Range(,)) = 

         _Mask("Mask(RG)",2D) = ""{}
     }
     SubShader {
         Tags { "RenderType"="Opaque" }
         LOD 

         CGPROGRAM
         #pragma surface surf Lambert
         // #pragma surface surf Lambert vertex:vert
         #pragma target 4.0

         sampler2D _RTexture,_GTexture,_BTexture,_ATexture;
         sampler2D _RNormalTex,_GNormalTex,_BNormalTex,_ANormalTex;
         float _RNormalIntensity,_GNormalIntensity,_BNormalIntensity,_ANormalIntensity;
         float _IllumFactor;

         sampler2D _Mask;

         struct Input {
             float2 uv_RTexture;
             float2 uv_GTexture;
             float2 uv_BTexture;
             float2 uv_ATexture;
             float2 uv_RNormalTex;
             float2 uv_GNormalTex;
             float2 uv_BNormalTex;
             float2 uv_ANormalTex;
             float2 uv_Mask;
         //    float3 m_normal;
         };
         void surf (Input IN, inout SurfaceOutput o) {
             float4 rTexData = tex2D(_RTexture, IN.uv_RTexture);
             float4 gTexData = tex2D(_GTexture, IN.uv_GTexture);
             float4 bTexData = tex2D(_BTexture, IN.uv_BTexture);
             float4 aTexData = tex2D(_ATexture, IN.uv_ATexture);
             float4 blendData = tex2D(_Mask, IN.uv_Mask);

             float4 finalColor;
             //根据blendData.g 将 RTexture 和 GTexture 混合
             finalColor = lerp(rTexData, gTexData, blendData.g);
             //根据blendData.b 将 BTexture 混合
             finalColor = lerp(finalColor, bTexData, blendData.b);
             //根据blendData.a 将 ATexture 混合
             finalColor = lerp(finalColor, aTexData , blendData.a);
             finalColor = saturate(finalColor);

             float3 rNormalMap = UnpackNormal(tex2D(_RNormalTex, IN.uv_RNormalTex));
             rNormalMap.xy*=_RNormalIntensity;
             float3 gNormalMap = UnpackNormal(tex2D(_GNormalTex, IN.uv_GNormalTex));
             gNormalMap.xy*=_GNormalIntensity;
             float3 bNormalMap = UnpackNormal(tex2D(_BNormalTex, IN.uv_BNormalTex));
             bNormalMap.xy*=_BNormalIntensity;
             //bNormalMap.z=sqrt(1.0-saturate(dot(bNormalMap.xy,bNormalMap.xy)));这个似乎并没有效果
             float3 aNormalMap = UnpackNormal(tex2D(_ANormalTex, IN.uv_ANormalTex));
             aNormalMap.xy*=_ANormalIntensity;

             float3 finalNormal;
             //根据blendData.g 将 RTexture 和 GTexture 混合
             finalNormal = lerp(rNormalMap, gNormalMap, blendData.g);
             //根据blendData.b 将 BTexture 混合
             finalNormal = lerp(finalNormal, bNormalMap, blendData.b);
             //根据blendData.a 将 ATexture 混合
             finalNormal = lerp(finalNormal, aNormalMap , blendData.a);

             o.Albedo =finalColor*_IllumFactor;
             o.Alpha = finalColor.a;
             o.Normal=finalNormal;
             //o.Normal=rNormalMap*blendData.r+gNormalMap*blendData.g+bNormalMap*blendData.b+aNormalMap*blendData.a;
         }
         ENDCG
     }
     FallBack "Diffuse"
 }

BlendNormalTex_surface

 Shader "Custom/BlendNormalTex_vertfrag"
 {
 Properties
 {
     Tex0 ("Layer 0 (R)", 2D) = "white" {}
     Tex1 ("Layer 1 (G)", 2D) = "white" {}
     Tex2 ("Layer 2 (G)", 2D) = "white" {}
     Tex3 ("Layer 3 (A)", 2D) = "white" {}

     _Normal0("Normal 0 (A)", 2D) = "bump" {}
     _Normal1("Normal 1 (B)", 2D) = "bump" {}
     _Normal2("Normal 2 (G)", 2D) = "bump" {}
     _Normal3("Normal 3 (R)", 2D) = "bump" {}

     _BumpScale0("BumpScale 0", Range(-1.0,1.0)) = 1.0
     _BumpScale1("BumpScale 1", Range(-1.0, 1.0)) = 1.0
     _BumpScale2("BumpScale 2", Range(-1.0, 1.0)) = 1.0
     _BumpScale3("BumpScale 3", Range(-1.0, 1.0)) = 1.0
     _Control ("Control (RGBA)", 2D) = "red" {}
     _IllumFactor ("Illumin Factor", Range(,)) =
 }

 SubShader
 {
     Tags{ "Queue" = "Geometry+110"   }
     Pass
     {

         Tags{"LightMode" = "ForwardBase" }

         CGPROGRAM
             #pragma vertex vert
             #pragma fragment frag
             #pragma target 2.0
             #include "UnityCG.cginc"
             #include "Lighting.cginc"

             sampler2D _Control;
             //贴图及纹理
             sampler2D Tex0,Tex1,Tex2,Tex3;
             half4 Tex0_ST,Tex1_ST,Tex2_ST,Tex3_ST;
             //法线贴图及纹理
             sampler2D _Normal0,_Normal1,_Normal2,_Normal3;
             half4 _Normal0_ST,_Normal1_ST,_Normal2_ST,_Normal3_ST;
             half _BumpScale0, _BumpScale1, _BumpScale2, _BumpScale3;

             half _IllumFactor;
             half4 _Control_ST;

             struct v2f
             {
                 float4    pos : SV_POSITION;
                 float3 normal:NORMAL;
                 float4 tangnent:TANGENT;
                 half4  uv_Tex0:TEXCOORD0;
                 half4  uv_Tex1:TEXCOORD1;
                 half4  uv_Tex2:TEXCOORD2;
                 half4  uv_Tex3:TEXCOORD3;
                 half2  uv_Control:TEXCOORD4;
                 half3 lightDir:TEXCOORD5;
                 half3 viewDir:TEXCOORD6;
             }; 

             struct appdata
             {
                 float4 vertex : POSITION;
                 float4 texcoord : TEXCOORD0;
                 float4 tangent:TANGENT;
                 float3 normal:NORMAL;
             };

             v2f vert (appdata v)
             {
                 v2f o;
                 o.pos =  mul(UNITY_MATRIX_MVP, v.vertex);
                 o.uv_Control = v.texcoord.xy;
                 o.uv_Tex0.xy = TRANSFORM_TEX(v.texcoord ,Tex0);
                 o.uv_Tex0.zw = TRANSFORM_TEX(v.texcoord ,_Normal0);

                 o.uv_Tex1.xy = TRANSFORM_TEX(v.texcoord ,Tex1);
                 o.uv_Tex1.zw = TRANSFORM_TEX(v.texcoord ,_Normal1);

                 o.uv_Tex2.xy = TRANSFORM_TEX(v.texcoord, Tex2);
                 o.uv_Tex2.zw = TRANSFORM_TEX(v.texcoord ,_Normal2);

                 o.uv_Tex3.xy = TRANSFORM_TEX(v.texcoord, Tex3);
                 o.uv_Tex3.zw = TRANSFORM_TEX(v.texcoord ,_Normal3);

                 TANGENT_SPACE_ROTATION;
                 o.lightDir=mul(rotation,ObjSpaceLightDir(v.vertex)).xyz;
                 o.viewDir=mul(rotation,ObjSpaceViewDir(v.vertex)).xyz;

                 return o;
             }
             fixed4 frag(v2f i):SV_Target
             {
                 fixed3 tangentLightDir=normalize(i.lightDir);
                 fixed3 tangentViewDir=normalize(i.viewDir);//暂时没用到,用于补充高光

                 fixed4 splat_control = tex2D (_Control, i.uv_Control.xy);

                 fixed3 tangentNormal0=UnpackNormal(tex2D(_Normal0, i.uv_Tex0.zw));
                 tangentNormal0.xy*=_BumpScale0;

                 fixed3 tangentNormal1=UnpackNormal(tex2D(_Normal1, i.uv_Tex1.zw));
                 tangentNormal1.xy*=_BumpScale1;

                   fixed3 tangentNormal2=UnpackNormal(tex2D(_Normal2, i.uv_Tex2.zw));
                 tangentNormal2.xy*=_BumpScale2;

                   fixed3 tangentNormal3=UnpackNormal(tex2D(_Normal3, i.uv_Tex3.zw));
                 tangentNormal3.xy*=_BumpScale3;

                 fixed4 albedo = 0.0f;

                 fixed4 Tex0Color = tex2D(Tex0, i.uv_Tex0);
                 fixed4 Tex1Color = tex2D(Tex1, i.uv_Tex1);
                 fixed4 Tex2Color = tex2D(Tex2, i.uv_Tex2);
                 fixed4 Tex3Color = tex2D(Tex3, i.uv_Tex3);

                 albedo = lerp(Tex0Color*max(, dot(tangentNormal1, tangentLightDir)),Tex1Color*max(, dot(tangentNormal1, tangentLightDir)), splat_control.g);
                 albedo = lerp(albedo,Tex2Color*max(, dot(tangentNormal2, tangentLightDir)), splat_control.b);
                 albedo = lerp(albedo,Tex3Color*max(, dot(tangentNormal3, tangentLightDir)), splat_control.a);

                 return albedo*_IllumFactor;
             }
         ENDCG
     }
 }
 FallBack "Diffuse"
 }

BlendNormalTex_vertfrag

效果：

albedo = lerp(Tex0Color,Tex1Color, splat_control.g);

//splat_control.g*Tex0Color+(1-splat_control.g)*Tex1Color

工程文件：http://files.cnblogs.com/files/luxishi/BlendShader.rar