UnityShaderBook/Assets/Shaders/Extra/GrabPass/DepthShader1.shader

Shader "Unlit/DepthShader1"
{
	Properties
	{
		_DepthScale("DepthData",Float) = 0.1
	}
	SubShader
	{
		Tags { "RenderType"="Opaque" "Queue"="Transparent" }
		LOD 100
		Pass
		{
			CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag
			
			#include "UnityCG.cginc"

			sampler2D _CameraDepthTexture;
			float _DepthScale;

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

			struct v2f
			{
				float2 uv : TEXCOORD0;
				float4 vertex : SV_POSITION;
				float4 scrPos : TEXCOORD1;
			};
			
			v2f vert (appdata v)
			{
				v2f o;
				o.vertex = UnityObjectToClipPos(v.vertex);
				o.uv = v.uv;
				o.scrPos = ComputeGrabScreenPos(o.vertex);
				return o;
			}
			
			fixed4 frag (v2f i) : SV_Target
			{
				// sample the texture
				//fixed4 refrCol = tex2D(_RefractionTex,i.uv);
				fixed4 refrCol = tex2D(_CameraDepthTexture, i.scrPos.xy/i.scrPos.w);
				float depth = SAMPLE_DEPTH_TEXTURE(_CameraDepthTexture, i.uv);
				float linearDepth = LinearEyeDepth(refrCol.r);
				float diff = linearDepth - i.scrPos.w;
				fixed4 intersect = fixed4(1,1,1,1)-fixed4(diff*_DepthScale,diff*_DepthScale,diff*_DepthScale,1);
				fixed4 border = saturate(intersect);
				return border;
			}
			ENDCG
		}
	}
}