Edge blend shader

Shader "Custom/EdgeBlend" {
	Properties {
		blendFactor ("Edge blend", Range(0.01,5)) = .15
	}
	Subshader {
		Tags {"RenderType"="Transparent" "Queue"="Transparent"}

		Lod 500
		ColorMask RGB

		Pass {
				Blend SrcAlpha OneMinusSrcAlpha
				ZTest LEqual
				ZWrite Off
				Cull Off

				CGPROGRAM

				#pragma target 3.0

				#pragma vertex vert
				#pragma fragment frag

				ENDCG
		}

		CGINCLUDE

		#include "UnityCG.cginc"

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

		struct v2f
		{
			float4 pos : SV_POSITION;
			float4 screenPos : TEXCOORD3;

		};

		sampler2D_float _CameraDepthTexture;
		float blendFactor;

		v2f vert(appdata_full v)
		{
			v2f o;
			o.pos = mul(UNITY_MATRIX_MVP, v.vertex);//
			o.screenPos = ComputeNonStereoScreenPos(o.pos);
			return o;
		}

		half4 frag( v2f i ) : SV_Target
		{

			half depth = SAMPLE_DEPTH_TEXTURE_PROJ(_CameraDepthTexture, UNITY_PROJ_COORD(i.screenPos));
			depth = LinearEyeDepth(depth);
			float baseColour = saturate(blendFactor * (depth-i.screenPos.w)).x;

			return baseColour;
		}


		ENDCG
	}
}