A simple outline shader for unity

OutlineShader.shader

Shader "Unlit/OutlineShader" {
	Properties {
		[HDR] _OutlineColor ("Outline Color", Color) = (1,1,1,1)
		_OutlineRadius ("Outline Radius", Float) = 0.1
	}
	SubShader {
		Tags { "RenderType"="Opaque" }
		LOD 100

		Pass {
			Stencil {
				Ref 2
				Comp always
				Pass replace
			}
			ColorMask 0
			ZTest LEqual
			ZWrite off

			CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag

			#include "UnityCG.cginc"

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

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

			sampler2D _MainTex;
			float4 _MainTex_ST;

			v2f vert (appdata v) {
				v2f o;
				o.vertex = UnityObjectToClipPos(v.vertex);
				return o;
			}

			fixed4 frag (v2f i) : SV_Target {
				return fixed4(1,1,1,1);
			}
			ENDCG
		}
		Pass {
			Stencil {
				Ref 2
				Comp notequal
				Pass zero
				ZFail zero
			}

			CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag

			#include "UnityCG.cginc"

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

			struct v2f {
				float4 vertex : SV_POSITION;
			};

			half4 _OutlineColor;
			half _OutlineRadius;

			v2f vert (appdata v) {
				v2f o;
				float3 clipNormal = normalize(mul((float3x3) UNITY_MATRIX_VP, mul((float3x3) UNITY_MATRIX_M, v.normal)));
				float4 clipPosition = UnityObjectToClipPos(v.vertex);
				clipPosition.xyz += clipNormal * _OutlineRadius;
				float2 offset = normalize(clipNormal.xy) * _OutlineRadius * clipPosition.w;
				clipPosition.xy += offset;
				o.vertex = clipPosition;
				return o;
			}

			fixed4 frag (v2f i) : SV_Target {
				return _OutlineColor;
			}
			ENDCG
		}
	}
}