Problem with a script in c#

Unity Engine
1

I created a script that allows controller to keep moving where I marked him even if I chose a different controller.

The script works twice then it stops working and gives me back the same error message 500 times per sec:

MissingReferenceException: The object of type ‘GameObject’ has been destroyed but you are still trying to access it.
Your script should either check if it is null or you should not destroy the object.
keepMoving.FixedUpdate () (at Assets/Controller/keepMoving.cs:26)

The script:

using UnityEngine;
using System.Collections;

public class keepMoving : MonoBehaviour {

	private Transform standardPos;
	private GameObject controllerPosition;
	private GameObject playerPosition;
	private Vector3 DistanceV;
	private float Distance;
	private float Movement;
	public float MovementSpeed = 10F;
	private Quaternion targetRotation;
	
	void Start () 
	{
		playerPosition = GameObject.Find("PlayerNewPosition");
		controllerPosition = new GameObject("controllerPosition");
		controllerPosition.transform.position = playerPosition.transform.position;
		standardPos = GameObject.Find("controllerPosition").transform;
		Destroy(playerPosition);
	}
	
	void FixedUpdate()
	{
		targetRotation = Quaternion.LookRotation(controllerPosition.transform.position - transform.position);
	    controllerPosition.transform.rotation = targetRotation;
		
		DistanceV = new Vector3(standardPos.position.x - transform.position.x, 0, standardPos.position.z - transform.position.z);
		Distance = Mathf.Sqrt(DistanceV.x*DistanceV.x + DistanceV.z*DistanceV.z);
		Movement = Time.deltaTime * MovementSpeed;
		
		if (Distance > Movement)
		{
			transform.Translate(0, 0, Movement);
			if (Mathf.Sqrt(DistanceV.x*DistanceV.x + DistanceV.z*DistanceV.z) < 0.01f)
			{
				Destroy(controllerPosition);
				GetComponent<keepMoving>().enabled = false;
			}
		}
		else if (Distance > 0.01f)
		{
			transform.Translate(0, 0, Distance);
			Destroy(controllerPosition);
			GetComponent<keepMoving>().enabled = false;
		}
		else 
		{
			Destroy(controllerPosition);
			GetComponent<keepMoving>().enabled = false;
		}
	}
	
}

The part where I call the script from the main script (line 9):

			ray = Camera.main.ScreenPointToRay(Input.mousePosition);
			if (Physics.Raycast (ray, out hitInfo))
			{
				if (hitInfo.transform.tag == "Player")
				{
					if (PlayerNewPosition != null)
					{
						MovementExam = false;
						GetComponent<keepMoving>().enabled = true;
						if (PlayerNewPosition != null)
						{
							Destroy(PlayerNewPosition);
						}
					}
					MoveWithMouse script = hitInfo.transform.gameObject.GetComponentInChildren<MoveWithMouse>();
					if (script)
					{
						script.enabled = true;
						GetComponent<MoveWithMouse>().enabled = false;
					}
				}
2

Obviously at some point you destroy the object when you shouldn’t.

You destroy it, but you are still trying to access it on line 26. If this is the behavior you want
just make a check ( != null ).

Start is called once, when the object is created, not at the start of each frame.
FixedUpdate is called 60 times a second.

3

I changed the script and now it does not work at all

NullReferenceException
UnityEngine.Transform.get_position () (at C:/BuildAgent/work/812c4f5049264fad/Runtime/ExportGenerated/Editor/UnityEngineTransform.cs:19)
keepMoving.FixedUpdate () (at Assets/Controller/keepMoving.cs:36)

using UnityEngine;
using System.Collections;

public class keepMoving : MonoBehaviour {

	private Transform standardPos;
	private GameObject controllerPosition;
	private GameObject playerPosition;
	private Vector3 DistanceV;
	private float Distance;
	private float Movement;
	public float MovementSpeed = 10F;
	private Quaternion targetRotation;
	
	void FixedUpdate()
	{
		if (controllerPosition == null)
		{
			playerPosition = GameObject.Find("PlayerNewPosition");
			controllerPosition = new GameObject("controllerPosition");
			controllerPosition.transform.position = playerPosition.transform.position;
			standardPos = GameObject.Find("controllerPosition").transform;
			targetRotation = Quaternion.LookRotation(controllerPosition.transform.position - transform.position);
		    controllerPosition.transform.rotation = targetRotation;
			Destroy(playerPosition);
		}
		
		targetRotation = Quaternion.LookRotation(controllerPosition.transform.position - transform.position);
	    controllerPosition.transform.rotation = targetRotation;
		
		DistanceV = new Vector3(standardPos.position.x - transform.position.x, 0, standardPos.position.z - transform.position.z);
		Distance = Mathf.Sqrt(DistanceV.x*DistanceV.x + DistanceV.z*DistanceV.z);
		Movement = Time.deltaTime * MovementSpeed;
		
		if (Distance > Movement)
		{
			transform.Translate(0, 0, Movement);
			if (Mathf.Sqrt(DistanceV.x*DistanceV.x + DistanceV.z*DistanceV.z) < 0.01f)
			{
				Destroy(controllerPosition);
				GetComponent<keepMoving>().enabled = false;
			}
		}
		else if (Distance > 0.01f)
		{
			transform.Translate(0, 0, Distance);
			Destroy(controllerPosition);
			GetComponent<keepMoving>().enabled = false;
		}
		else 
		{
			Destroy(controllerPosition);
			GetComponent<keepMoving>().enabled = false;
		}
	}
	
}
4

I tried your script with 2 cubes and it works.

Be sure your objects name are correct and try to Debug.Log () the content once your try to reach them to be sure it finds them.

5

I found the mistake turns out it was the second script, thanks anyway :slight_smile: