Unity 5.5：使用着色器渲染网格交点？ （图片）

Question

我正在尝试制作一个单一的着色器，检查它是否与网格物体（使用相同的着色器）发生碰撞，如果有，则根本不应该渲染该碰撞部分。对于两个网格。

我正试图获得这种效果：

我使用横断面着色器来实现这一点，但这不是我想要的：

这是着色器代码：

    // Upgrade NOTE: replaced 'glstate.matrix.invtrans.modelview[0]' with 'UNITY_MATRIX_IT_MV'
// Upgrade NOTE: replaced 'glstate.matrix.mvp' with 'UNITY_MATRIX_MVP'

// 2 Pass Edition

Shader "cross_section_v004a"
{
    Properties 
    {
        section_depth ("section depth (x, y, z, depth)", vector) = (0,0,0,0.15)
        section_color ("section color", color) = (0.5,0.1, 0.1, 1)

        color_map ("color map", 2D) = "white" {}

    }   
    SubShader 
    {   
        Pass
        {           
            CULL OFF

CGPROGRAM //--------------
//#pragma target 3.0
#pragma vertex   vertex_shader
#pragma fragment fragment_shader

#include "UnityCG.cginc"

uniform float4 section_depth;
uniform float4 section_color;
uniform sampler2D color_map;    

float4x4 rotate(float3 r) 
{ 
    float3 c, s; 
    sincos(r.x, s.x, c.x); 
    sincos(r.y, s.y, c.y); 
    sincos(r.z, s.z, c.z);
    return float4x4( c.y*c.z,    -s.z,     s.y, 0, 
                         s.z, c.x*c.z,    -s.x, 0, 
                        -s.y,     s.x, c.x*c.y, 0, 
                           0,       0,       0, 1 );
} 

struct a2v 
{
    float4 vertex   : POSITION;
    float4 color    : COLOR;
    float2 texcoord : TEXCOORD;
    float3 normal   : NORMAL;
};

struct v2f
{
    float4 position : POSITION;
    float2 texcoord : TEXCOORD0;                                
    float4 normal   : TEXCOORD1; 
    float4 vertex   : TEXCOORD2;
    float4 mask     : TEXCOORD3;                
};

v2f vertex_shader( a2v IN )
{                                                   
    v2f OUT;

    float4x4 r   = rotate(radians(section_depth.xyz) +_SinTime.xyz);
    float4 c     = float4(IN.vertex.xyz,1);

    OUT.mask     = mul(r, c);
    OUT.position = mul(UNITY_MATRIX_MVP, IN.vertex);
    OUT.texcoord = IN.texcoord;

    r *= float4x4(   1,-1,-1, 0,
                    -1, 1,-1, 0,
                    -1,-1, 1, 0,
                     0, 0, 0, 1 ); // the section_depth.xyz need to be inverted !

    OUT.normal   = mul(r, float4(1,0,0,1));
    OUT.vertex   = IN.vertex;

    return OUT;
}

void fragment_shader(   v2f IN,
                        out float4 finalcolor : COLOR)  

{
    if(IN.mask.x > section_depth.w)
        discard;

    float3 N = IN.normal.xyz;

    N = mul(UNITY_MATRIX_IT_MV, float4(N, 1));              
    //float diffuse = saturate(dot(glstate.light[0].position, N));  

    finalcolor = float4(0,0,0,1);                               
    finalcolor.xyz = section_color *(0.6 +0.4);
}
ENDCG //--------------

        } // Pass

//---------------------------------------------------------------------------------

        Pass
        {           
            CULL BACK

CGPROGRAM //--------------
#pragma vertex   vertex_shader
#pragma fragment fragment_shader

#include "UnityCG.cginc"

uniform float4 section_depth;
uniform float4 section_color;
uniform sampler2D color_map;    

float4x4 rotate(float3 r) 
{ 
    float3 c, s; 
    sincos(r.x, s.x, c.x); 
    sincos(r.y, s.y, c.y); 
    sincos(r.z, s.z, c.z);
    return float4x4( c.y*c.z,    -s.z,     s.y, 0, 
                         s.z, c.x*c.z,    -s.x, 0, 
                        -s.y,     s.x, c.x*c.y, 0, 
                           0,       0,       0, 1 );
} 

struct a2v 
{
    float4 vertex   : POSITION;
    float4 color    : COLOR;
    float2 texcoord : TEXCOORD;
    float3 normal   : NORMAL;
};

struct v2f
{
    float4 position : POSITION;
    float2 texcoord : TEXCOORD0;                                
    float3 normal   : TEXCOORD1; 
    float4 vertex   : TEXCOORD2;
    float4 mask     : TEXCOORD3;                
};

v2f vertex_shader( a2v IN )
{                                                   
    v2f OUT;

    float4x4 r   = rotate(radians(section_depth.xyz) +_SinTime.xyz);
    float4 c     = float4(IN.vertex.xyz,1);

    OUT.mask     = mul(r, c);
    OUT.position = mul(UNITY_MATRIX_MVP, IN.vertex);
    OUT.texcoord = IN.texcoord;
    OUT.normal   = IN.normal;
    OUT.vertex   = IN.vertex;

    return OUT;
}

void fragment_shader(   v2f IN,
                        out float4 finalcolor : COLOR)  

{
    if(IN.mask.x > section_depth.w)
        discard;

    float3 N = IN.normal;

    N = mul(UNITY_MATRIX_IT_MV, float4(N, 1));              
    //float diffuse = saturate(dot(glstate.light[0].position, N));

    finalcolor = float4(0,0,0,1);                                           
    finalcolor.xyz = tex2D(color_map, IN.texcoord).xyz *(0.6 +0.4);
}
ENDCG //--------------

        } // Pass

    } // SubShader
} // Shader

然而，对象的其余部分应该是可见的，我的意思是说我不希望不相交的部分是不可见的（当从不可见的部分查看时），因此模板着色器不会或不是不要这么做。像这样的东西：

我想知道解决这个问题的正确方法是什么。我对着色器编程很新，我不知道要解决这个问题。任何帮助将不胜感激。

谢谢！