1

This is my code to crate a quad but as the title says the quad is crated in local space and not world.

Mesh CrateMeshChunk()
	{	
  		V1 = Me.transform.position;
		V2 = NeighbourTop.transform.position;
		V3 = NeighbourLeft.transform.position;
		V4 = NeighbourLeft.GetComponent<Neighbour>().NeighbourTop.transform.position;

		Mesh mesh = new Mesh();

     	Vector3[] vertices = new Vector3[]
     	{
        	 V1,V2,V3,V4,
     	};
 
     	Vector2[] uv = new Vector2[]
     	{
			UV1,UV2,UV3,UV4,
     	};
 	
 	    int[] triangles = new int[]
 	    {
 	        0, 1, 2,
 	        2, 1, 3,
 	    };
 	
 	    mesh.vertices = vertices;
 	    mesh.uv = uv;
 	    mesh.triangles = triangles;
 	
 	    return mesh;
 	}
2

The mesh.vertices are in local space relative to its attached gameObject, maybe you should transform the vertex position from world to local:

V1 = quadTransform.InverseTransformPoint(Me.transform.position);
 V2 = quadTransform.InverseTransformPoint(NeighbourTop.transform.position);
 V3 = quadTransform.InverseTransformPoint(NeighbourLeft.transform.position);
 V4 = quadTransform.InverseTransformPoint(NeighbourLeft.GetComponent<Neighbour>().NeighbourTop.transform.position);

Yword