Screen mask shader with noise

// Upgrade NOTE: replaced '_Object2World' with 'unity_ObjectToWorld'

Shader "Custom/FogShader"
{
	Properties
	{
		_MainTex("Fog texture", 2D) = "white" {}
		_MainTex2("Fog texture 2", 2D) = "white" {}
		_FogColorFactor("Fog color factor", Float) = 1
		_FogScroll("Fog scroll speed", vector) = (0,0,0,0)
		_FogMap("Fog map", 2D) = "white" {}
		_NoiseTex("Noise texture", 2D) = "white" {}
		_NoiseTex2("Noise texture 2", 2D) = "white" {}
		_NoiseScroll("Noise offset speed", vector) = (0,0,0,0)
		_NoiseFactor("Noise factor", Float) = 0.005
		//_BlurAmount("Blur Amount", Range(0,02)) = 0.0005
	}

	SubShader
	{
		Tags{ "Queue" = "Transparent" "IgnoreProjector" = "True" "RenderType" = "Transparent" }
		//LOD 100
		ZWrite Off
		Blend SrcAlpha OneMinusSrcAlpha

		Pass
		{
			CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag

			#include "UnityCG.cginc"

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

			struct v2f
			{
				float4 uv : TEXCOORD0;
				float4 screenpos : TEXCOORD2;
				float4 vertex : SV_POSITION;
				float4 noiseUv : TEXCOORD3;
			};

			sampler2D _MainTex;
			float4 _MainTex_ST;
			
			sampler2D _MainTex2;
			float4 _MainTex2_ST;

			sampler2D _FogMap;
			float _NoiseFactor;

			sampler2D _NoiseTex;
			float4 _NoiseTex_ST;

			sampler2D _NoiseTex2;
			float4 _NoiseTex2_ST;

			float4 _NoiseScroll;
			float4 _FogScroll;
			float _FogColorFactor;
			//float _BlurAmount;

			v2f vert(appdata v)
			{
				v2f o;
				o.vertex = UnityObjectToClipPos(v.vertex);
				
				o.uv.xy = TRANSFORM_TEX(v.uv, _MainTex);
				o.uv.zw = TRANSFORM_TEX(v.uv, _MainTex2);
				o.uv -= _Time.yyyy * _FogScroll;

				o.screenpos = ComputeScreenPos(o.vertex);

				float2 xz = mul(unity_ObjectToWorld, v.vertex).xz;
				float2 noiseUv = TRANSFORM_TEX(xz, _NoiseTex);
				float2 noiseUv2 = TRANSFORM_TEX(xz, _NoiseTex2);
				o.noiseUv = float4(noiseUv, noiseUv2);
				o.noiseUv -= _Time.yyyy * _NoiseScroll;
				return o;
			}

			fixed4 frag(v2f i) : SV_Target
			{
				fixed4 col = tex2D(_MainTex, i.uv.xy) * tex2D(_MainTex2, i.uv.zw) * _FogColorFactor;

				float2 maskUv = i.screenpos.xy / i.screenpos.w;
				half2 noise = tex2D(_NoiseTex, i.noiseUv.xy).rg;
				half2 noise2 = tex2D(_NoiseTex2, i.noiseUv.zw).rg;
				half2 noiseMix = noise * noise2;

				maskUv += (noiseMix * 2 - 1) * _NoiseFactor;
				//no blur
				col.a *= (1 - tex2D(_FogMap, maskUv).r);

				//blur
				//half fogcol = half(0);
				//float remaining = 1.0f;
				//float coef = 1.0;
				//float fI = 0;
				//for (int j = 0; j < 3; j++) {
				//	fI++;
				//	coef *= 0.32;
				//	fogcol += (1 - tex2D(_FogMap, float2(maskUv.x, maskUv.y - fI * _BlurAmount))) * coef;
				//	fogcol += (1 - tex2D(_FogMap, float2(maskUv.x - fI * _BlurAmount, maskUv.y))) * coef;
				//	fogcol += (1 - tex2D(_FogMap, float2(maskUv.x + fI * _BlurAmount, maskUv.y))) * coef;
				//	fogcol += (1 - tex2D(_FogMap, float2(maskUv.x, maskUv.y + fI * _BlurAmount))) * coef;

				//	remaining -= 4 * coef;
				//}
				//col.a *= fogcol + (1 - tex2D(_FogMap, float2(maskUv.x, maskUv.y))) * remaining;
				return col;
			}
			ENDCG
		}
	}
}