Shader教程：描边效果

Shader "Water Wave" ｛
    Properties ｛
        _Color ("Main Color", Color) = (0, 0.15, 0.115, 1)
        _MainTex ("Base (RGB)", 2D) = "white" ｛｝
        _NormalTex ("Wave Map", 2D) = "bump" ｛｝
        _Cubemap ("Environment Cubemap", Cube) = "_Skybox" ｛｝
        _WaterXSpeed ("Wave Horizontal Speed", Range(-0.1, 0.1)) = 0.01
        _WaterYSpeed ("Wave Vertical Speed", Range(-0.1, 0.1)) = 0.01
        _Distortion ("Distortion", Range(0, 100)) = 10
    ｝
    SubShader ｛
        // We must be transparent, so other objects are drawn before this one.
        Tags ｛ "Queue"="Transparent" "RenderType"="Opaque" ｝
        // This pass grabs the screen behind the object into a texture.
        // We can access the result in the next pass as _RefractionTex
        GrabPass ｛ "_RefractionTex" ｝
        Pass ｛
            Tags ｛ "LightMode"="ForwardBase" ｝
            CGPROGRAM
            #include "UnityCG.cginc"
            #include "Lighting.cginc"
            #pragma multi_compile_fwdbase
            #pragma vertex vert
            #pragma fragment frag
            fixed4 _Color;
            sampler2D _MainTex;
            float4 _MainTex_ST;
            sampler2D _NormalTex;
            float4 _NormalTex_ST;
            samplerCUBE _Cubemap;
            fixed _WaterXSpeed;
            fixed _WaterYSpeed;
            float _Distortion;  
            sampler2D _RefractionTex;
            float4 _RefractionTex_TexelSize;
            struct a2v ｛
                float4 vertex : POSITION;
                float3 normal : NORMAL;
                float4 tangent : TANGENT; 
                float4 texcoord : TEXCOORD0;
            ｝;
            struct v2f ｛
                float4 pos : SV_POSITION;
                float4 scrPos : TEXCOORD0;
                float4 uv : TEXCOORD1;
                float4 TtoW0 : TEXCOORD2;  
                float4 TtoW1 : TEXCOORD3;  
                float4 TtoW2 : TEXCOORD4; 
            ｝;
            v2f vert(a2v v) ｛
                v2f o;
                o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
                // 抓取对应屏幕坐标
                o.scrPos = ComputeGrabScreenPos(o.pos);
                o.uv.xy = TRANSFORM_TEX(v.texcoord, _MainTex);
                o.uv.zw = TRANSFORM_TEX(v.texcoord, _NormalTex);
                // 法线图的切线空间转换到世界空间用
                float3 worldPos = mul(unity_ObjectToWorld, v.vertex).xyz;  
                fixed3 worldNormal = UnityObjectToWorldNormal(v.normal);  
                fixed3 worldTangent = UnityObjectToWorldDir(v.tangent.xyz);  
                fixed3 worldBinormal = cross(worldNormal, worldTangent) * v.tangent.w; 
                o.TtoW0 = float4(worldTangent.x, worldBinormal.x, worldNormal.x, worldPos.x);  
                o.TtoW1 = float4(worldTangent.y, worldBinormal.y, worldNormal.y, worldPos.y);  
                o.TtoW2 = float4(worldTangent.z, worldBinormal.z, worldNormal.z, worldPos.z);  
                return o;
            ｝
            fixed4 frag(v2f i) : SV_Target ｛
                // 空间转换
                float3 worldPos = float3(i.TtoW0.w, i.TtoW1.w, i.TtoW2.w);
                fixed3 viewDir = normalize(UnityWorldSpaceViewDir(worldPos));
                float2 speed = _Time.y * float2(_WaterXSpeed, _WaterYSpeed);
                // Get the normal in tangent space
                fixed3 bump1 = UnpackNormal(tex2D(_NormalTex, i.uv.zw + speed)).rgb;
                fixed3 bump2 = UnpackNormal(tex2D(_NormalTex, i.uv.zw - speed)).rgb;
                fixed3 bump = normalize(bump1 + bump2);
                // Compute the offset in tangent space
                float2 offset = bump.xy * _Distortion * _RefractionTex_TexelSize.xy;
                i.scrPos.xy = offset * i.scrPos.z + i.scrPos.xy;
                fixed3 refrCol = tex2D( _RefractionTex, i.scrPos.xy/i.scrPos.w).rgb;
                // Convert the normal to world space
                bump = normalize(half3(dot(i.TtoW0.xyz, bump), dot(i.TtoW1.xyz, bump), dot(i.TtoW2.xyz, bump)));
                fixed4 texColor = tex2D(_MainTex, i.uv.xy + speed);
                fixed3 reflDir = reflect(-viewDir, bump);
                fixed3 reflCol = texCUBE(_Cubemap, reflDir).rgb * texColor.rgb * _Color.rgb;
                fixed fresnel = pow(1 - saturate(dot(viewDir, bump)), 4);
                fixed3 finalColor = reflCol * fresnel + refrCol * (1 - fresnel);
                return fixed4(finalColor, 1);
            ｝
            ENDCG
        ｝
    ｝
    // Do not cast shadow
    FallBack Off
｝