基本原理：被遮擋的部分關閉深度寫入， 顯示透明效果；未被遮擋的部分不關閉深度測試，顯示正常貼圖效果，即使用兩個Pass即可。

Pass1：關閉深度寫入（ZWrite Off），深度測試渲染較遠的物體，即模型被物體遮擋的部分（ztest greater）。

Pass2：開啟深度寫入，正常渲染。

 1 Shader "xj/Character/Normal" {
 2     Properties {
 3         _Color ("Main Color", Color) = (1,1,1,1)
 4         _MainTex ("Base (RGB) Trans (A)
 
", 2D) = "white" {}
 5         _intensity ("Intensity", float ) = 1.0
 6 
 7         _RimColor("RimColor",Color) = (0,1,1,1)
 8         _RimPower ("Rim Power", Range(0.1,8.0)) = 1.0
 9     }
10 
11 
12     SubShader
13     {
14         LOD 300  
15         Tags { "Queue" = "Geometry+500" "RenderType
 
"="Opaque" } 
16         Pass
17         {
18             Blend SrcAlpha One
19             ZWrite off
20             Lighting off
21  
22             ztest greater
23  
24             CGPROGRAM
25             #pragma vertex vert
26             #pragma fragment frag
27             #include "
 
UnityCG.cginc"
28  
29             float4 _RimColor;
30             float _RimPower;
31             
32             struct appdata_t {
33                 float4 vertex : POSITION;
34                 float2 texcoord : TEXCOORD0;
35                 float4 color:COLOR;
36                 float4 normal:NORMAL;
37             };
38  
39             struct v2f {
40                 float4  pos : SV_POSITION;
41                 float4  color:COLOR;
42             } ;
43             v2f vert (appdata_t v)
44             {
45                 v2f o;
46                 o.pos = mul(UNITY_MATRIX_MVP,v.vertex);
47                 float3 viewDir = normalize(ObjSpaceViewDir(v.vertex)); 
48                 //視線與法線垂直的部分（點乘為0）即是外輪廓，加重描繪
49                 float rim = 1 - saturate(dot(viewDir,v.normal )); 
50                 o.color = _RimColor*pow(rim,_RimPower);
51                 return o;
52             }
53             float4 frag (v2f i) : COLOR
54             {
55                 return i.color; 
56             }
57             ENDCG
58         }
59         Pass {  
60             CGPROGRAM
61                 #pragma vertex vert
62                 #pragma fragment frag
63                 #pragma fragmentoption ARB_precision_hint_fastest
64                 
65                 #include "UnityCG.cginc"
66 
67                 struct appdata_t {
68                     float4 vertex : POSITION;
69                     half2 texcoord : TEXCOORD0;
70                 };
71 
72                 struct v2f {
73                     float4 vertex : SV_POSITION;
74                     half2 texcoord : TEXCOORD0;
75                 };
76 
77                 sampler2D _MainTex;
78                 fixed4 _Color;
79                 fixed _intensity;
80                 
81                 v2f vert (appdata_t v)
82                 {
83                     v2f o;
84                     o.vertex = mul(UNITY_MATRIX_MVP,v.vertex);
85                     o.texcoord = v.texcoord;
86                     return o;
87                 }
88                 
89                 fixed4 frag (v2f i) : SV_Target
90                 {
91                     fixed4 col = tex2D(_MainTex, i.texcoord) * _Color * _intensity;
92                     return col;
93                 }
94             ENDCG
95         }
96     }
97 }