Trying to Add Basic Transparency to Shader

Questions & Answers
1

Hi, I’m trying to add an overall transparency parameter to this shader so I can fade it in/out, any help would be hugely appreciated:

Properties
	{
		_MainTex ("Texture", 2D) = "black" {}
		_YTex("Y channel", 2D) = "black" {}
		_UTex("U channel", 2D) = "gray" {}
		_VTex("V channel", 2D) = "gray" {}
	}
	SubShader
	{
		Tags { "RenderType"="Opaque" }
		LOD 100

		Pass
		{
			CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag
			// make fog work
			#pragma multi_compile_fog
			
			#include "UnityCG.cginc"

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

			struct v2f
			{
				float2 uv : TEXCOORD0;
				UNITY_FOG_COORDS(1)
				float4 vertex : SV_POSITION;
			};

			sampler2D _MainTex;
			sampler2D _YTex;
			sampler2D _UTex;
			sampler2D _VTex;
			float4 _MainTex_ST;
			
			v2f vert (appdata v)
			{
				v2f o;
				o.vertex = mul(UNITY_MATRIX_MVP, v.vertex);
				o.uv = TRANSFORM_TEX(v.uv, _MainTex);
				UNITY_TRANSFER_FOG(o,o.vertex);
				return o;
			}
			
			fixed4 frag (v2f i) : SV_Target
			{
				float2 inv_uv = float2(i.uv.x, 1.0 - i.uv.y);
				float ych = tex2D(_YTex, inv_uv).a;
				float uch = tex2D(_UTex, inv_uv).a * 0.872 - 0.436;		//	Scale from 0 ~ 1 to -0.436 ~ +0.436
				float vch = tex2D(_VTex, inv_uv).a * 1.230 - 0.615;		//	Scale from 0 ~ 1 to -0.615 ~ +0.615
				/*	BT.601	*/
				float rch = clamp(ych + 1.13983 * vch, 0.0, 1.0);
				float gch = clamp(ych - 0.39465 * uch - 0.58060 * vch, 0.0, 1.0);
				float bch = clamp(ych + 2.03211 * uch, 0.0, 1.0);
				
				fixed4 col = fixed4(rch, gch, bch, 1.0);
				col = pow(col, 2.2);
				UNITY_APPLY_FOG(i.fogCoord, col);
				return col;
			}
			ENDCG
		}
	}
2

Properties
{
_MainTex (“Texture”, 2D) = “black” {}
_Alpha (“Transparency”, Range(0,1)) = 1.0
_YTex(“Y channel”, 2D) = “black” {}
_UTex(“U channel”, 2D) = “gray” {}
_VTex(“V channel”, 2D) = “gray” {}
}
SubShader
{
Tags { “RenderType”=“Transparent” “Queue”=“Transparent” }
LOD 100

             Pass
             {
                 Blend SrcAlpha OneMinusSrcAlpha
                 CGPROGRAM
                 #pragma vertex vert
                 #pragma fragment frag
                 // make fog work
                 #pragma multi_compile_fog
                 
                 #include "UnityCG.cginc"
     
                 struct appdata
                 {
                     float4 vertex : POSITION;
                     float2 uv : TEXCOORD0;
                 };
     
                 struct v2f
                 {
                     float2 uv : TEXCOORD0;
                     UNITY_FOG_COORDS(1)
                     float4 vertex : SV_POSITION;
                 };
     
                 sampler2D _MainTex;
                 sampler2D _YTex;
                 sampler2D _UTex;
                 sampler2D _VTex;
                 half _Alpha;
                 float4 _MainTex_ST;
                 
                 v2f vert (appdata v)
                 {
                     v2f o;
                     o.vertex = mul(UNITY_MATRIX_MVP, v.vertex);
                     o.uv = TRANSFORM_TEX(v.uv, _MainTex);
                     UNITY_TRANSFER_FOG(o,o.vertex);
                     return o;
                 }
                 
                 fixed4 frag (v2f i) : SV_Target
                 {
                     float2 inv_uv = float2(i.uv.x, 1.0 - i.uv.y);
                     float ych = tex2D(_YTex, inv_uv).a;
                     float uch = tex2D(_UTex, inv_uv).a * 0.872 - 0.436;        //    Scale from 0 ~ 1 to -0.436 ~ +0.436
                     float vch = tex2D(_VTex, inv_uv).a * 1.230 - 0.615;        //    Scale from 0 ~ 1 to -0.615 ~ +0.615
                     /*    BT.601    */
                     float rch = clamp(ych + 1.13983 * vch, 0.0, 1.0);
                     float gch = clamp(ych - 0.39465 * uch - 0.58060 * vch, 0.0, 1.0);
                     float bch = clamp(ych + 2.03211 * uch, 0.0, 1.0);
                     
                     fixed4 col = fixed4(rch, gch, bch, 1.0);
                     col = pow(col, 2.2);
                     col.a = _Alpha;
                     UNITY_APPLY_FOG(i.fogCoord, col);
                     return col;
                 }
                 ENDCG
             }
         }

Just be wary that fog probably wont work with transparency.