RaycastHit2D

Unity Engine
1

Hello, I have this code:

private RaycastHit2D ray;

    private void FlyBuildingItems()
    {
            Vector3 MousePosition = Camera.ScreenToWorldPoint(Input.mousePosition);
             ray = Physics2D.Raycast(MousePosition, -Vector2.zero);

            if (Input.GetMouseButton(0))
            {
                if (ray.collider.CompareTag("Build"))
                    IsBeingDragger = true;
                }
            }
        }

It works as I intended, but when I click on an object without a collider, it gives the error “NullReferenceException: Object reference not set to an instance of an object”, the error itself does not interfere with the code in any way, but it catches the eye.
How can I fix it ?

2

ALWAYS the same way, ALWAYS.

How to fix a NullReferenceException error

https://forum.unity.com/threads/how-to-fix-a-nullreferenceexception-error.1230297/

Steps to success:

  • Identify what is null
  • Identify why it is null
  • Fix that
2 Likes
3

If you look at any code example for raycast it always makes sure that the raycast actually hit something before proceeding using an if statement. You should follow that pattern:

3 Likes
4

Also, don’t use a degenerate raycast (length or direction of zero) to effectively check a point. Because it’s 2D, you only need to use Physics2D.OverlapPoint and pass in the world-space position of the mouse.

It’s faster and more efficient to use the correct 2D techniques rather than stuff that’s been adapted from 3D.

1 Like