【Unity2D】遮蔽物と重なった部分をシルエットにするシェーダー【Shader】

StencilShield.shader

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

		Pass
		{
			Stencil//ステンシルテスト
			{
				Ref 1
				Comp Always
				Pass Replace
			}

			CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag

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

			struct v2f
			{
				float2 uv : TEXCOORD0;
				float4 vertex : SV_POSITION;
			};

			sampler2D _MainTex;
			
			v2f vert (appdata v)
			{
				v2f o;
				o.vertex = UnityObjectToClipPos(v.vertex);
				o.uv=v.uv;
				return o;
			}
			
			fixed4 frag (v2f i) : SV_Target
			{
				fixed4 col = tex2D(_MainTex, i.uv);
				return col;
			}
			ENDCG
		}
	}
}

StencilSilhouetteObj.shader

Shader "Unlit/StencilSilhouetteObj"
{
	Properties
	{
		_MainTex ("Texture", 2D) = "white" {}
	}
	SubShader
	{
		Tags { "RenderType"="Opaque" }
		LOD 100
		Blend SrcAlpha OneMinusSrcAlpha 

		Pass//Ref 1のマテリアルと重なったら黒く塗り潰す
		{
			Stencil//ステンシルテスト
			{
				Ref 1
				Comp Equal
			}

			CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag

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

			struct v2f
			{
				float2 uv : TEXCOORD0;
				float4 vertex : SV_POSITION;
			};

			sampler2D _MainTex;
			
			v2f vert (appdata v)
			{
				v2f o;
				o.vertex = UnityObjectToClipPos(v.vertex);
				o.uv = v.uv;
				return o;
			}
			
			fixed4 frag (v2f i) : SV_Target
			{				
				fixed alpha=tex2D(_MainTex, i.uv).a;
				fixed4 col = fixed4(0,0,0,alpha);
				return col;
			}
			ENDCG
		}

		Pass
		{
			Stencil//ステンシルテスト
			{
				Ref 0//オブジェクト部分じゃないとこは0
				Comp Equal
			}

			CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag

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

			struct v2f
			{
				float2 uv : TEXCOORD0;
				float4 vertex : SV_POSITION;
			};

			sampler2D _MainTex;
			
			v2f vert (appdata v)
			{
				v2f o;
				o.vertex = UnityObjectToClipPos(v.vertex);
				o.uv = v.uv;
				return o;
			}
			
			fixed4 frag (v2f i) : SV_Target
			{				
				fixed4 col = tex2D(_MainTex, i.uv);
				return col;
			}
			ENDCG
		}
	}
}