Unity3dShader边缘发光效果

shader知识：http://imgtec.eetrend.com/blogs/%E5%A2%A8%E5%8D%8A%E6%88%90%E9%9C%9C

最终效果

Shader "Learning Unity Shader/Lecture 14/Basic Rim Shader"  
{  
    //-----------------------------------【属性 || Properties】------------------------------------------   
    Properties  
    {  
        //主颜色 || Main Color  
        _MainColor("【主颜色】Main Color", Color) = (0.5,0.5,0.5,1)  
        //漫反射纹理 || Diffuse Texture  
        _TextureDiffuse("【漫反射纹理】Texture Diffuse", 2D) = "white" {}   
        //边缘发光颜色 || Rim Color  
        _RimColor("【边缘发光颜色】Rim Color", Color) = (0.5,0.5,0.5,1)  
        //边缘发光强度 ||Rim Power  
        _RimPower("【边缘发光强度】Rim Power", Range(0.0, 36)) = 0.1  
        //边缘发光强度系数 || Rim Intensity Factor  
        _RimIntensity("【边缘发光强度系数】Rim Intensity", Range(0.0, 100)) = 3  
    }  
   
    //----------------------------------【子着色器 || SubShader】---------------------------------------   
    SubShader  
    {  
        //渲染类型为Opaque，不透明 || RenderType Opaque  
        Tags  
        {  
            "RenderType" = "Opaque" 
        }  
   
        //---------------------------------------【唯一的通道 || Pass】------------------------------------  
        Pass  
        {  
            //设定通道名称 || Set Pass Name  
            Name "ForwardBase" 
   
            //设置光照模式 || LightMode ForwardBase  
            Tags  
            {  
                "LightMode" = "ForwardBase" 
            }  
   
            //-------------------------开启CG着色器编程语言段 || Begin CG Programming Part----------------------   
            CGPROGRAM  
   
                //【1】指定顶点和片段着色函数名称 || Set the name of vertex and fragment shader function  
                #pragma vertex vert  
                #pragma fragment frag  
   
                //【2】头文件包含 || include  
                #include "UnityCG.cginc"  
                #include "AutoLight.cginc"  
   
                //【3】指定Shader Model 3.0 || Set Shader Model 3.0  
                #pragma target 3.0  
   
                //【4】变量声明 || Variable Declaration  
                //系统光照颜色  
                uniform float4 _LightColor0;  
                //主颜色  
                uniform float4 _MainColor;  
                //漫反射纹理  
                uniform sampler2D _TextureDiffuse;   
                //漫反射纹理_ST后缀版  
                uniform float4 _TextureDiffuse_ST;  
                //边缘光颜色  
                uniform float4 _RimColor;  
                //边缘光强度  
                uniform float _RimPower;  
                //边缘光强度系数  
                uniform float _RimIntensity;  
   
                //【5】顶点输入结构体 || Vertex Input Struct  
                struct VertexInput   
                {  
                    //顶点位置 || Vertex position  
                    float4 vertex : POSITION;  
                    //法线向量坐标 || Normal vector coordinates  
                    float3 normal : NORMAL;  
                    //一级纹理坐标 || Primary texture coordinates  
                    float4 texcoord : TEXCOORD0;  
                };  
   
                //【6】顶点输出结构体 || Vertex Output Struct  
                struct VertexOutput   
                {  
                    //像素位置 || Pixel position  
                    float4 pos : SV_POSITION;  
                    //一级纹理坐标 || Primary texture coordinates  
                    float4 texcoord : TEXCOORD0;  
                    //法线向量坐标 || Normal vector coordinates  
                    float3 normal : NORMAL;  
                    //世界空间中的坐标位置 || Coordinate position in world space  
                    float4 posWorld : TEXCOORD1;  
                    //创建光源坐标,用于内置的光照 || Function in AutoLight.cginc to create light coordinates  
                    LIGHTING_COORDS(3,4)  
                };  
   
                //【7】顶点着色函数 || Vertex Shader Function  
                VertexOutput vert(VertexInput v)   
                {  
                    //【1】声明一个顶点输出结构对象 || Declares a vertex output structure object  
                    VertexOutput o;  
   
                    //【2】填充此输出结构 || Fill the output structure  
                    //将输入纹理坐标赋值给输出纹理坐标  
                    o.texcoord = v.texcoord;  
                    //获取顶点在世界空间中的法线向量坐标   
                    o.normal = mul(float4(v.normal,0), _World2Object).xyz;  
                    //获得顶点在世界空间中的位置坐标   
                    o.posWorld = mul(_Object2World, v.vertex);  
                    //获取像素位置  
                    o.pos = mul(UNITY_MATRIX_MVP, v.vertex);  
   
                    //【3】返回此输出结构对象  || Returns the output structure  
                    return o;  
                }  
   
                //【8】片段着色函数 || Fragment Shader Function  
                fixed4 frag(VertexOutput i) : COLOR  
                {  
                    //【8.1】方向参数准备 || Direction  
                    //视角方向  
                    float3 ViewDirection = normalize(_WorldSpaceCameraPos.xyz - i.posWorld.xyz);  
                    //法线方向  
                    float3 Normalection = normalize(i.normal);  
                    //光照方向  
                    float3 LightDirection = normalize(_WorldSpaceLightPos0.xyz);  
   
                    //【8.2】计算光照的衰减 || Lighting attenuation  
                    //衰减值  
                    float Attenuation = LIGHT_ATTENUATION(i);  
                    //衰减后颜色值  
                    float3 AttenColor = Attenuation * _LightColor0.xyz;  
   
                    //【8.3】计算漫反射 || Diffuse  
                    float NdotL = dot(Normalection, LightDirection);  
                    float3 Diffuse = max(0.0, NdotL) * AttenColor + UNITY_LIGHTMODEL_AMBIENT.xyz;  
   
                    //【8.4】准备自发光参数 || Emissive  
                    //计算边缘强度  
                    half Rim = 1.0 - max(0, dot(i.normal, ViewDirection));  
                    //计算出边缘自发光强度  
                    float3 Emissive = _RimColor.rgb * pow(Rim,_RimPower) *_RimIntensity;  
   
                    //【8.5】计在最终颜色中加入自发光颜色 || Calculate the final color  
                    //最终颜色 = （漫反射系数 x 纹理颜色 x rgb颜色）+自发光颜色 || Final Color=(Diffuse x Texture x rgbColor)+Emissive  
                    float3 finalColor = Diffuse * (tex2D(_TextureDiffuse,TRANSFORM_TEX(i.texcoord.rg, _TextureDiffuse)).rgb*_MainColor.rgb) + Emissive;  
                   
                    //【8.6】返回最终颜色 || Return final color  
                    return fixed4(finalColor,1);  
                }  
   
            //-------------------结束CG着色器编程语言段 || End CG Programming Part------------------   
            ENDCG  
        }  
    }  
   
    //后备着色器为普通漫反射 || Fallback use Diffuse  
    FallBack "Diffuse" 
}