unity-shader stencil模板测试简单应用蒙皮遮罩Mask

本文详细介绍如何在Unity中使用Shader结合Stencil Mask实现精确的图形裁剪效果。通过对比未添加与添加Shader后的变化，清晰展示Stencil Mask如何精确控制渲染区域，避免不必要的图形绘制，提高渲染效率。

未添加shader前：
在这里插入图片描述
添加shader后：

可以看到在mask外的部分全部被“裁剪”了
对代码中的命令不清楚可以查看上一篇中的介绍：

Shader "Unlit/stencil_maskAdd"
{
    Properties
    {
        _MainTex ("Texture", 2D) = "white" {}
    }
    SubShader
    {
        Tags {"Queue"="Geometry+2" "RenderType"="Opaque" }
        LOD 100

        Pass
        {
            Stencil
            {
                Ref 5
                Comp Equal
                Pass Replace
            }
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            // make fog work
            #pragma multi_compile_fog

            #include "UnityCG.cginc"

            struct appdata
            {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
            };

            struct v2f
            {
                float2 uv : TEXCOORD0;
                UNITY_FOG_COORDS(1)
                float4 vertex : SV_POSITION;
            };

            sampler2D _MainTex;
            float4 _MainTex_ST;

            v2f vert (appdata v)
            {
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.uv = TRANSFORM_TEX(v.uv, _MainTex);
                UNITY_TRANSFER_FOG(o,o.vertex);
                return o;
            }

            fixed4 frag (v2f i) : SV_Target
            {
                // sample the texture
                fixed4 col = tex2D(_MainTex, i.uv);
                // apply fog
                UNITY_APPLY_FOG(i.fogCoord, col);
                return col;
            }
            ENDCG
        }
    }
}

Shader "Unlit/stencil_maskBase"
{
    Properties
    {
        _MainTex ("Texture", 2D) = "white" {}
    }
    SubShader
    {
        Tags {"Queue"="Geometry+1" "RenderType"="Opaque" }
        LOD 100

        Pass
        {
            Stencil
            {
                Ref 5
                Comp Always
                Pass Replace
            }
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            // make fog work
            #pragma multi_compile_fog

            #include "UnityCG.cginc"

            struct appdata
            {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
            };

            struct v2f
            {
                float2 uv : TEXCOORD0;
                UNITY_FOG_COORDS(1)
                float4 vertex : SV_POSITION;
            };

            sampler2D _MainTex;
            float4 _MainTex_ST;

            v2f vert (appdata v)
            {
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.uv = TRANSFORM_TEX(v.uv, _MainTex);
                UNITY_TRANSFER_FOG(o,o.vertex);
                return o;
            }

            fixed4 frag (v2f i) : SV_Target
            {
                // sample the texture
                fixed4 col = tex2D(_MainTex, i.uv);
                // apply fog
                UNITY_APPLY_FOG(i.fogCoord, col);
                return col;
            }
            ENDCG
        }
    }
}