[SOLVED] Position Crosshair with Raycast

I can't figure out why this code isn't working. In my 3D spaceship game I have a raycast coming out of the ship's muzzle (empty game object) and I am trying to position a crosshair (UI image) where the raycast hits.

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class CrosshairTest : MonoBehaviour {
6.  
7.  
8.     public Transform crosshair;
9.     public Camera cam;
10.     public Transform muzzle;
11.  
12.     void Update ()
13.     {
14.         RaycastHit hit;
15.         if (Physics.Raycast(muzzle.transform.position, muzzle.transform.forward, out hit))
16.         {
17.             if (hit.collider)
18.             {
19.                 crosshair.transform.position = cam.WorldToViewportPoint(hit.point);
20.             }
21.         }
22.     }  
23. }

In the game window the crosshair just stays in the bottom left corner. What am I doing wrong?

 

switch to cam.WorldToScreenPoint(hit.point);

I'm assuming 'crosshair' is a UI Image Component? If so change it to RectTransform. If you do that do

crosshair.position = cam.WorldToScreenPoint(hit.point);

 

@TheHighGround beat me to it.

 

That did the trick! Thank you! Just so I better understand for future work, why did it need to be WorldToScreenPoint instead of WorldToViewportPoint?

 

Camera.WorldToViewPort API TLDR: a viewport is a normalized Vector2 you get a value from 0.0F to 1.0F. On the XAxis the left most part of the screen would be 0.0F and the right most port of the screen would be 1.0F.

Camera.WorldToScreenPoint API TLDR: a screen point is the raw Vector2 that represents the screen in pixels. So if you have a screen that is 1920x1080 the coordinate (x,y) a UI RectTransform.position component would be placed would be relative to that screen size.

 

Graciasssss