Rim 边缘光

边缘光：计算眼睛和模型顶点法线的点积，结果作为强度，和材质输出；顶点和法线平行时，强度最大，垂直时，强度最小。因此将他取反，即同一方向时，强度最小，垂直时，强度最大。

float rim= 1-dot(normalize(viewDirection),normalDirection);

源代码：

 1 Shader "JQM/Rim_1"
 2 {
 3     Properties
 4     {
 5         _Color("Color", color) = (1.0,1.0,1.0,1.0)
 6         _SpecColor("Specular Color", color) = (1.0,1.0,1.0,1.0)
 7         _Shininess("Shininess",float) = 10
 8         _RimColor("Rim Coloe Color", color) = (1.0,1.0,1.0,1.0)
 9         _RimPower("Rim Power",Range(0.1,10.0)) = 3.0
10
11     }
12     SubShader{
13         Pass{
14
15             Tags { "LightMode" = "ForwardBase"}
16
17             CGPROGRAM
18             #pragma vertex vert
19             #pragma fragment frag
20
21             //使用自定义变量
22             uniform float4 _Color;
23             uniform float4 _SpecColor;
24             uniform float4 _RimColor;
25             uniform float _Shininess;
26             uniform float _RimPower;
27
28             //使用Unity定义的变量
29             uniform float4 _LightColor0;
30
31             struct vertexInput{
32                 float4 vertex:POSITION;
33                 float3 normal:NORMAL;
34             };
35
36             struct vertexOutput{
37                 float4 pos:SV_POSITION;
38                 float4 posWorld:TEXCOORD0;
39                 float3 normalDir:TEXCOORD1;
40             };
41
42             //顶点程序
43             vertexOutput vert(vertexInput v)
44             {
45                 vertexOutput o;
46                 o.posWorld = mul(_Object2World, v.vertex);
47                 o.normalDir =  normalize( mul(float4(v.normal,0.0),_World2Object).xyz);
48                 o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
49                 return o;
50             }
51
52             //片段程序
53             float4 frag(vertexOutput i):COLOR
54             {
55                 float3 normalDirection = i.normalDir;
56                 float3 viewDirection = normalize(_WorldSpaceCameraPos.xyz- i.posWorld.xyz);
57
58                 float rim=1 -dot(normalize(viewDirection),normalDirection);
59                 return float4(rim*_Color.xyz,1.0);
60             }
61
62             ENDCG
63         }
64     }
65
66 }