【Unity Shader】插入 Pass 实现模型遮挡 X 光透视效果

//原Pass不变，插入一个Pass，用于显示模型遮挡部分 Shader "Test/Model_XRay"{		Properties	{		_MainTex ("Diffuse (RGB)", 2D) = "grey" {}		_Color("Color (RGBA)", Color) = (1,1,1,1) 		_XRayColor("XRay Color", Color) = (1,1,1,1)	}		SubShader	{		Tags        {            "RenderType"="Opaque"            "Queue"="AlphaTest+1"            "IgnoreProjector"="True"        } 		LOD 200		Fog { Mode Off } 		//渲染X光透视效果的Pass		Pass		{			Blend SrcAlpha One			ZWrite Off			ZTest Greater 			CGPROGRAM 			#pragma vertex vert			#pragma fragment frag 			#include "Lighting.cginc" 			fixed4 _XRayColor; 			struct v2f			{				float4 pos : SV_POSITION;				float3 normal : normal;				float3 viewDir : TEXCOORD0;			}; 			v2f vert (appdata_base v)			{				v2f o;				o.pos = UnityObjectToClipPos(v.vertex);				o.viewDir = ObjSpaceViewDir(v.vertex);		//计算顶点到相机的向量				o.normal = v.normal;				return o;			} 			fixed4 frag(v2f i) : SV_Target			{				//利用法线跟视线向量的点乘值计算颜色浓度				float3 normal = normalize(i.normal);				float3 viewDir = normalize(i.viewDir);				float rim = 1 - dot(normal, viewDir);				return _XRayColor * rim;			} 			ENDCG		} 		Pass		{            CGPROGRAM             //定义顶点/片元着色器代码            #pragma vertex vert            #pragma fragment frag             #include "UnityCG.cginc"             sampler2D _MainTex;                  //定义顶点着色器的输入            struct a2v            {                float4 vertex : POSITION;                float2 uv :TEXCOORD0;            };            //定义顶点着色器的输出、片元着色器的输入            struct v2f            {                float4 vertex : SV_POSITION;                float2 uv:TEXCOORD0;            };             v2f vert (a2v v)            {                v2f o;                o.vertex = UnityObjectToClipPos(v.vertex);                o.uv = v.uv;                return o;            }               fixed4 frag (v2f i) : SV_Target            {                return tex2D(_MainTex,i.uv);            }            ENDCG 		} 	}	FallBack "Diffuse"}