ScreenToWorldPoint() not working

Question

Hi,

I'm currently experimenting with ScreenToWorldPoint(), and something just doesn't seem to be working right...

Whenever I use this code:

 function Update() {
 Debug.Log(camera.ScreenToWorldPoint(Input.mousePosition));
 }

It just shows (0.0 ,125.0, 0.0) all the time in the Debug console, regardless of how much I move the cursor around the screen.

How can I make my code display the actual world coordinates my mouse is currently passing over?

Thanks in advance. :)

Answer 1

Best Answer

Answer by aldonaletto · Oct 12, 2012 at 09:03 PM

ScreenToWorldPoint receives a Vector3 argument where x and y are the screen coordinates, and z is the distance from the camera. Since Input.mousePosition.z is always 0, what you're getting is the camera position.
The mouse position in the 2D screen corresponds to a line in the 3D world passing through the camera center and the mouse pointer, thus you must somehow select which point in this line you're interested in - that's why you must pass the distance from the camera in z.
If you try something like this:

 function Update() {
   var mousePos = Input.mousePosition;
   mousePos.z = 10; // select distance = 10 units from the camera
   Debug.Log(camera.ScreenToWorldPoint(mousePos));
 }

you will get the world point at 10 units from the camera.

Add comment · Show 6 · Share

THEpancakes · Oct 13, 2012 at 09:07 PM 0

Share

thanks, that worked perfectly :)

Fattie · Mar 11, 2014 at 04:17 PM 0

Share

don't forget ut's different when you are orthographic!

felixpk · Apr 15, 2014 at 12:54 PM 0

Share

Hey it still does not work for me :(

        BoxCollider2D destroyBox =   Camera.main.GetComponent<BoxCollider2D>();
         colliderPos = camera.ScreenToWorldPoint(new Vector3(0, 0, -10));
 
         Vector2 posXY = new Vector2(colliderPos.x,colliderPos.y);
         destroyBox.center = posXY;

I want the BoxCollider2D to be on the left side of the Camera, all it does is positioning it about 1 unit left from the center of the camera... anyone an idea?

Sarseth · Jul 19, 2015 at 11:17 AM 0

Share

Almost. But it works only when player is standing in place. I'm moving camera with player, and then it does not work. This is not the true position of the mouse in the map. Only relative to center.

manhngovan · Apr 04, 2017 at 10:37 AM 0

Share

Thank you, @aldonaletto! I'm newbie. Your answer is the only one that make me understand how to use ScreenToWorldPoint. I don't understand until see your answer. I don't know where to like or give you 1point I'm having.

Show more comments

Answer 2

Answer by Eric5h5 · Oct 12, 2012 at 08:52 PM

You have to specify a Z position, like the code example in the docs does.

Add comment · Share

ScreenToWorldPoint() not working

2 Replies

Your answer

Follow this Question

Related Questions