How to change the color of a UI cross hair using Raycasts

Questions & Answers
1

Hello, I need help with a certain problem I am having with Unity 5. I have created a raycasting script in C# that simply allows me to destroy a certain object under the tag, “Objects”.

I have also imported a custom UI cursor that I want the color changing of, through bool animations, when a certain object is being hovered over.

using UnityEngine;
using System.Collections;

public class CursorChange : MonoBehaviour {

	public float distanceToSee;
	RaycastHit hit;  
	Animator anim;

	// Use this for initialization
	void Start () {
		anim = GetComponent<Animator> ();
		Cursor.visible = (false);
		anim.SetBool ("hasHit", false); 
	}
	
	// Update is called once per frame
	void Update () 
	{
		if(Physics.Raycast(this.transform.position, this.transform.forward, out hit, distanceToSee))
		{
			if(hit.collider.tag == "Objects")
			{
				anim.SetBool ("hasHit", true);
			}
		}
	}
}

There are no compiler errors from this script yet the desired results are still not showing. Can anybody help?

2

Where’s this script attached?

Even if you have this on your camera, there’s not really a 1-1 relation between directly forward from your camera and where the screen is.

To find out what you’re looking at, use Camera.ScreenPointToRay - it creates a ray from the camera to the screen coordinates you input.

So, if you’re using a free mouse, you want something like:

Ray ray = Camera.ScreenPointToRay(Input.MousePosition);
if(Physics.Raycast(ray, out hit, ...)

If you’re using mouse look, you’ll want to use the center of the screen instead:

Ray ray = Camera.ScreenPointToRay(new Vector3(Screen.width / 2, Screen.height / 2, 0));
if(Physics.Raycast(ray, out hit, ...)

Good luck!