使用截止着色器Unity3d组合香椿着色器

Question

我想添加一个alpha截止选项（带有从检查器控制的滑块）到toon基本轮廓着色器。下面粘贴了两个需要合并的着色器的代码：

香椿着色器：

Shader "Toon/Basic Outline-Cutoff" {
    Properties {
        _Color ("Main Color", Color) = (.5,.5,.5,1)
        _OutlineColor ("Outline Color", Color) = (0,0,0,1)
        _Outline ("Outline width", Range (.002, 0.03)) = .005
        _MainTex ("Base (RGB)", 2D) = "white" { }
        _ToonShade ("ToonShader Cubemap(RGB)", CUBE) = "" { Texgen CubeNormal }
    }

    CGINCLUDE
    #include "UnityCG.cginc"

    struct appdata {
        float4 vertex : POSITION;
        float3 normal : NORMAL;
    };

    struct v2f {
        float4 pos : POSITION;
        float4 color : COLOR;
    };

    uniform float _Outline;
    uniform float4 _OutlineColor;

    v2f vert(appdata v) {
        v2f o;
        o.pos = mul(UNITY_MATRIX_MVP, v.vertex);

        float3 norm   = mul ((float3x3)UNITY_MATRIX_IT_MV, v.normal);
        float2 offset = TransformViewToProjection(norm.xy);

        o.pos.xy += offset * o.pos.z * _Outline;
        o.color = _OutlineColor;
        return o;
    }
    ENDCG

    SubShader {
        Tags { "RenderType"="Opaque" }
        UsePass "Toon/Basic/BASE"
        Pass {
            Name "OUTLINE"
            Tags { "LightMode" = "Always" }
            Cull Front
            ZWrite On
            ColorMask RGB
            Blend SrcAlpha OneMinusSrcAlpha

            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            half4 frag(v2f i) :COLOR { return i.color; }
            ENDCG
        }
    }

    SubShader {
        Tags { "RenderType"="Opaque" }
        UsePass "Toon/Basic/BASE"
        Pass {
            Name "OUTLINE"
            Tags { "LightMode" = "Always" }
            Cull Front
            ZWrite On
            ColorMask RGB
            Blend SrcAlpha OneMinusSrcAlpha

            CGPROGRAM
            #pragma vertex vert
            #pragma exclude_renderers shaderonly
            ENDCG
            SetTexture [_MainTex] { combine primary }
        }
    }

    Fallback "Toon/Basic"
}

---

alpha截止着色器：

Shader "Custom/alpha_cutoff" {
Properties
{
    _Color ("Main Color", Color) = (1,1,1,1)
    _MainTex ("Texture", 2D) = "white" {}
    _Cutoff ("Alpha cutoff", Range(0,1)) = 0.5
}

SubShader
{
    Cull Off
    Tags
    {
        "Queue" = "Transparent"
        "IgnoreProjector" = "True"
        "RenderType" = "TransparentCutoff"
    }
    Pass
    {
        Blend SrcAlpha One
        Alphatest Greater [_Cutoff]
        AlphaToMask True
        ColorMask RGB


        SetTexture [_MainTex]
        {
            Combine texture, texture
        }
        SetTexture [_MainTex] {
            constantColor [_Color]
            Combine previous * constant, previous * constant
        }  
    }
}

}