Unity3d 外发光 Shader

转载自http://oulehui.blog.163.com/blog/static/79614698201233104558110/

Shader "Faye/OutLightting"
{
    Properties
    {
        _MainTex("Texture (RGB)", 2D) = "black" {}
        _Color("Color", Color) = (0, 0, 0, 1)
        _AtmoColor("Atmosphere Color", Color) = (0.5, 0.5, 1.0, 1)
        _Size("Size", Float) = 0.1
        _Falloff("Falloff", Float) = 5
        _FalloffPlanet("Falloff Planet", Float) = 5
        _Transparency("Transparency", Float) = 15
        _TransparencyPlanet("Transparency Planet", Float) = 1
    }
  
 SubShader
    {
        Pass
        {
            Name "PlanetBase"
            Tags {"LightMode" = "Always"}
            Cull Back
          
            CGPROGRAM
                #pragma vertex vert
                #pragma fragment frag
              
                #pragma fragmentoption ARB_fog_exp2
                #pragma fragmentoption ARB_precision_hint_fastest
              
                #include "UnityCG.cginc"
              
                uniform sampler2D _MainTex;
                uniform float4 _MainTex_ST;
                uniform float4 _Color;
                uniform float4 _AtmoColor;
                uniform float _FalloffPlanet;
                uniform float _TransparencyPlanet;
              
                struct v2f
                {
                    float4 pos : SV_POSITION;
                    float3 normal : TEXCOORD0;
                    float3 worldvertpos : TEXCOORD1;
                    float2 texcoord : TEXCOORD2;
                };

                v2f vert(appdata_base v)
                {
                    v2f o;
                  
                    o.pos = mul (UNITY_MATRIX_MVP, v.vertex);
                    o.normal = v.normal;
                    o.worldvertpos = mul(_Object2World, v.vertex).xyz;
                    o.texcoord = TRANSFORM_TEX(v.texcoord, _MainTex);
                  
                    return o;
                }
             
                float4 frag(v2f i) : COLOR
                {
                    i.normal = normalize(i.normal);
                    float3 viewdir = normalize(_WorldSpaceCameraPos-i.worldvertpos);
                  
                    float4 atmo = _AtmoColor;
                    atmo.a = pow(1.0-saturate(dot(viewdir, i.normal)), _FalloffPlanet);
                    atmo.a *= _TransparencyPlanet*_Color;
              
                    float4 color = tex2D(_MainTex, i.texcoord)*_Color;
                    color.rgb = lerp(color.rgb, atmo.rgb, atmo.a);
              
                    return color*dot(normalize(i.worldvertpos-_WorldSpaceLightPos0), i.normal);
                }
            ENDCG
        }
  
        Pass
        {
            Name "AtmosphereBase"
            Tags {"LightMode" = "Always"}
            Cull Front
            Blend SrcAlpha One
          
            CGPROGRAM
                #pragma vertex vert
                #pragma fragment frag
              
                #pragma fragmentoption ARB_fog_exp2
                #pragma fragmentoption ARB_precision_hint_fastest
              
                #include "UnityCG.cginc"
              
                uniform float4 _Color;
                uniform float4 _AtmoColor;
                uniform float _Size;
                uniform float _Falloff;
                uniform float _Transparency;
              
                struct v2f
                {
                    float4 pos : SV_POSITION;
                    float3 normal : TEXCOORD0;
                    float3 worldvertpos : TEXCOORD1;
                };

                v2f vert(appdata_base v)
                {
                    v2f o;
                  
                    v.vertex.xyz += v.normal*_Size;
                    o.pos = mul (UNITY_MATRIX_MVP, v.vertex);
                    o.normal = v.normal;
                    o.worldvertpos = mul(_Object2World, v.vertex);
                  
                    return o;
                }
             
                float4 frag(v2f i) : COLOR
                {
                    i.normal = normalize(i.normal);
                    float3 viewdir = normalize(i.worldvertpos-_WorldSpaceCameraPos);
                  
                    float4 color = _AtmoColor;
                    color.a = pow(saturate(dot(viewdir, i.normal)), _Falloff);
                    color.a *= _Transparency*_Color*dot(normalize(i.worldvertpos-_WorldSpaceLightPos0), i.normal);
                    return color;
                }
            ENDCG
        }
    }
  
    FallBack "Diffuse"
}