How to make the movement of an object equal to the mouse?

Question

Unity

Here I did almost what I need, it only moves slowly, it needs to be at the speed of the mouse, in general the essence is this, there is a panel and image objects on it, and now I need to move this panel in different directions with the mouse

public GameObject NewGameObject;
public Camera cam;
private float startx,starty, SpeedChange1;
private Vector3 dir1,dir2;

void Start () {
  SpeedChange1 = NewGameObject.transform.position.z-cam.transform.position.z;
  }

private void Update(){
  if (Input.GetMouseButtonDown (0)) {    
    startx = NewGameObject.transform.position.x;
    starty = NewGameObject.transform.position.y;
    dir1 = cam.ScreenToWorldPoint(new Vector3(Input.mousePosition.x,Input.mousePosition.y, SpeedChange1));
    } 
 if (Input.GetMouseButton (0)) {
    dir2 = cam.ScreenToWorldPoint(new Vector3(Input.mousePosition.x,Input.mousePosition.y, SpeedChange1));
    NewGameObject.transform.position = new Vector3((dir2.x-dir1.x)+startx, (dir2.y-dir1.y)+starty,
      NewGameObject.transform.position.z);
      }           
  }

It moves but slowly...
How to do it right?
Canvas - Screen Space Overlay
Scale with....

In short, there is an interface that cannot be touched, but there is a map that can be moved and enlarged....

Answer 1

You need to use raycast - you throw a ray, look where it hit and transfer the object there. Accordingly, there must be some kind of transparent substrate in order to move along its plane.