Unity图形学之边缘检测

1.边缘发光：

越是边缘的法线和光线入射角的夹角越大，值越小；

越是正中间的法线和光线的入射角的夹角越小，值越大；

Shader "Custom/NormalOutLine"
{
    Properties
    {
        _Color ("Color", Color) = (1,1,1,1)
        _MainTex ("Albedo (RGB)", 2D) = "white" {}
        _NorTex ("Normal Map (RGB)", 2D) = "white" {}
        _EmisionPower("EmisionPower",float) = 2
    }
    SubShader
    {
        Tags { "RenderType"="Opaque" }
        LOD 200
        CGPROGRAM
        // Physically based Standard lighting model, and enable shadows on all  light types
        #pragma surface surf Lambert
        // Use shader model 3.0 target, to get nicer looking lighting
        #pragma target 3.0
        sampler2D _MainTex;
        sampler2D _NorTex;
        float _EmisionPower;
        struct Input
        {
            float2 uv_MainTex;
            float2 uv_NorTex;
            float3 viewDir;
        };
        fixed4 _Color;
        void surf (Input IN, inout SurfaceOutput o)
        {
            // Albedo comes from a texture tinted by color
            fixed4 c = tex2D (_MainTex, IN.uv_MainTex);
            //读取法线
            float3  tempNormal =  UnpackNormal(tex2D (_NorTex, IN.uv_NorTex));
            o.Normal = tempNormal;
            //算出法线和视角的点乘
            float tempFloat = 1- clamp(dot(IN.viewDir,tempNormal),0,1);
            //自发光
            o.Emission = _Color * pow(tempFloat,_EmisionPower);
            o.Albedo = c.rgb;
            o.Alpha = c.a;
        }
        ENDCG
    }
    FallBack "Diffuse"
}