Question about sending physics raycast from the camera

Hi all,

I'm experiencing some issues with sending a raycast from the camera to check collision with an interactable object.

what I tried:

  private void MouseDown(Event e) {
             var ray = _mainCamera.ScreenPointToRay(e.mousePosition);
             Debug.DrawRay(ray.origin, ray.direction * hitMultiplier, Color.yellow, 10f);
             
             var isHit = Physics.Raycast(ray, out var hit, float.MaxValue);
             if (!isHit) return;
 }...

Outcome:

In the outcome, ray 1-3, are three rays created when pressing mouse click on the screen.

The issue is, only ray 2 is correct, while ray 1 and ray 3 indicates opposite directions. Specifically, pressing at the top of the screen, results in a ray at the button of the screen.

Ray 1 points to the direction, which is actually the direction of ray 3.

It seems the y value of e.MousePoistion.y is opposite.

Do you know why?

Its not a very expected behavior.