Enabling another script when entering a triggered plane (C#)

Questions & Answers
1

Hi all,

I’ve been working on a game where, as a first step, a group of objects start bouncing when they are approached by the player. So far I’ve solved this by creating a plane and placing it under the group of objects, and setting it as a trigger. Then, in my script PlayerControls, I’ve made an OnTriggerEnter function, where the Bouncing script is supposed to be enabled upon collision.

I did some searching, and wrote something that should work, but doesn’t. Instead I get the error NullReferenceException: Object reference not set to an instance of an object on the line startBouncing.enabled = false; in PlayerControls.
So apparently something goes wrong when referencing to the Bouncing script. However, I can’t find what goes wrong here as I don’t see the difference between my code and the ones referenced.

Note here that I tried disabling the Bouncing script as a first attempt instead of enabling it. Ideally, it would be disabled until I enabled it upon entering the trigger.

Here are the scripts I’ve got:

Bouncing

using UnityEngine;
using System.Collections;

public class Bouncing: MonoBehaviour {
	public bool Move = true;
	public Vector3 MoveVector = Vector3.up;
	//public float MoveRange = 0.00001f;
	//public float MoveSpeed = 0.2f;
	private Bouncing bounceObject;
	Vector3 startPosition;
	
	void Start ()
	{
		bounceObject = this;
		startPosition = bounceObject.transform.position;
	}
	// Update is called once per frame
	void Update () 
	{
		if(Move) {
			bounceObject.transform.position = startPosition + MoveVector * (0.5f * Mathf.Sin(Time.timeSinceLevelLoad * 3.3f));
		}
	}
}

PlayerControls

using UnityEngine;
using System.Collections;
using UnityEngine.UI;

public class PlayerControls : MonoBehaviour {
	public float speed;
	private Rigidbody rb;
	private Bouncing startBouncing;



	void Start ()
	{
		rb = GetComponent<Rigidbody>();
		startBouncing = GetComponent<Bouncing>();

	}

	void FixedUpdate ()
	{
		float moveHorizontal = Input.GetAxis ("Horizontal");
		float moveVertical = Input.GetAxis ("Vertical");

		Vector3 movement = new Vector3 (moveHorizontal, 0.0f, moveVertical);
		rb.AddForce (movement * speed);
	}
	void OnTriggerEnter(Collider other) 
	{
		if (other.gameObject.CompareTag("Pick Up"))
		{
			other.gameObject.SetActive (false);

		}
		if (other.gameObject.CompareTag("Plane"))
		{
			startBouncing.enabled = false;
		}
	}

}

Here’s the main reference that I used:
http://unity3d.com/learn/tutorials/modules/beginner/scripting/enabling-disabling-components

If anyone could help me out, I’d greatly appreciate it! I feel like I’m missing a tiny thing but I just can’t find it.

2

The error you get means that the startBouncing variable in your PlayerControls script is null. I see you have startBouncing = GetComponent(); in your Start() function, so that doesn’t work properly. Keep in mind that GetComponent() only gets components that are on the same gameObject, not ones that are in a child object (or on another one entirely). Maybe you should use GetComponentInChildren() there instead?