Bake a texture from shader

Hi, I am trying to bake a final result from shader to texture. the only t$$anonymous$$ng a shader does is apply second uv set on texture.

Here is the shader code :

 Shader "Custom/uv2Tex" {
     Properties {
         _MainTex ("Diffuse", 2D) = "w$$anonymous$$te" { }   
     }
     SubShader {
         Pass {
         CGPROGRAM
         #pragma vertex vert
         #pragma fragment frag
  
         sampler2D _MainTex;
  
        struct a2v {
             float4 vertex : POSITION;
             float2  texcoord : TEXCOORD0;
             float2 texcoord1 : TEXCOORD1;
         };
  
         struct v2f {
             float4 vertex : POSITION;
             float2  texcoord : TEXCOORD0;
             float2 texcoord1 : TEXCOORD1;
         };
  
         v2f vert (a2v v)
         {
             v2f o;
             o.vertex = mul( UNITY_MATRIX_MVP, v.vertex);          
             o.texcoord1 = v.texcoord1;
             return o;
         }
  
         half4 frag (v2f i) : COLOR
         {
             half4 color = tex2D(_MainTex, i.texcoord1);         
             return color;
         }
       
         ENDCG
         }
     }
 }

and here is the script that bakes the texture:

 using UnityEngine;
 using System.Collections;
 using System.IO;
 public class BakeVideo : MonoBehaviour {
     public Texture2D Maintexture;
     public RenderTexture RT;
     public Material bakeMat;
     public MeshRenderer Go;
 
     // Use t$$anonymous$$s for initialization
     IEnumerator Start () {
         
     
         yield return UploadPNG();
 
     }
     
     IEnumerator UploadPNG() 
     {
         yield return new WaitForEndOfFrame();
         bakeMat = Go.sharedMaterial;
         Maintexture = Go.sharedMaterial.GetTexture ("_MainTex") as Texture2D;
 
         Grap$$anonymous$$cs.Blit (Maintexture, RT, bakeMat);
         // Create a texture the size of the screen, RGB24 format
         RenderTexture.active = RT;
         Texture2D tex = new Texture2D(512,512);
 
         // Read screen contents into the texture
         tex.ReadPixels(new Rect(0, 0, 512, 512), 0, 0);
         tex.Apply();
 
         // Encode texture into PNG
         byte[] bytes = tex.EncodeToPNG();
         Object.Destroy(tex);
 
         // For testing purposes, also write to a file in the project folder
         File.WriteAllBytes(Application.dataPath + "/../SavedScreen.png", bytes);
     }
 
 }
 

The problem is that my result is always looking the same as the original texture, as if the Grap$$anonymous$$cs.Blit is not taking into account the uv alteration in shader? Is there a way to solve t$$anonymous$$s? Thanks