How to use a boolean to control another object boolean using C# script

Questions & Answers
1

Hi, I have a control panel and i want to use it to control the animation of a landing gear…
So this is the script i have written for the control panel which i can control using keydown and…

public class panel : MonoBehaviour {

public bool stick;
private Animator animator;
private GameObject player;

// Use this for initialization
void Start () {

	animator = GetComponent<Animator> ();
}

// Update is called once per frame
void OnTriggerStay(Collider other) {

	if (Input.GetKeyDown (KeyCode.P)) {
		animator.SetBool ("stick", true);
	}

	if (Input.GetKeyDown (KeyCode.O)) {
		animator.SetBool ("stick", false);
	}


}

this is the script i written for landing gear which i want it to detect the boolean is true or false from the control panel:

public class landinggear : MonoBehaviour {

private Animator anim;
private GameObject player;

// Use this for initialization
void Start () {

}

// Update is called once per frame
void Update () {

	if(GameObject.Find("panel").GetComponent<panel>().stick)
	{
		anim.SetBool("retraction",true);
	}

	if(!GameObject.Find("panel").GetComponent<panel>().stick)
	{
		anim.SetBool("retraction",false);
	}
}

}

So both object have its own animator, and i succeed to activate control panel but not the landing gear…
and I very new to C# scripting so anyone can stop by and help me with this…
thank you very much.

2

The problem is that your first script is only changing the ANIMATOR boolean value. NOT the actual boolean value. So you’ll need to change your stuff to

if(Input.GetKeyDown(KeyCode.P)){
    stick = true;
    animator.SetBool("stick", stick); //We're setting the bool value to the same as the "stick" variable so it only has to be set one time (more dynamic)
}

And do the same for the other one.

Now your landinggear script should work :slight_smile:

ALSO at the top of your landinggear script i’d recommend creating a “panel” reference at the top of your script.

So where you have your anim and player add in a

private panel pan;

and in Start()

pan = GameObject.Find("panel").GetComponent<panel>();

and then refer to pan instead of the GameObject.Find blah blah stuff

The reason for this is GameObject.Find(“blahblah”).GetComponent(); is VERY slow and calling it every frame can slow your game down. Setting up a reference to this “panel” you made is one, easier to write/read, and is also much faster :slight_smile:

3

You just need to reassign stick whenever you change the animation :

void OnTriggerStay(Collider other)
{
    if (Input.GetKeyDown(KeyCode.P))
    {
        animator.SetBool("stick", true);
        stick = true;
    }
    if (Input.GetKeyDown(KeyCode.O))
    {
        animator.SetBool("stick", false);
        stick = false;
    }
}

And in landinggear, don’t forget to get a reference for your anim :

void Start()
{
    anim = GetComponent<Animator>();
}

That should be enough to get your script working.

4

Really thanks for the reply @corn @SterlingSoftworks
So i have do some editing and still it shows error :

NullReferenceException: Object reference not set to an instance of an object
landinggear.Update () (at Assets/landinggear.cs:26)

script for panel:

public class panel : MonoBehaviour {

public bool stick;
private Animator animator;
private GameObject player;

// Use this for initialization
void Start () {

	animator = GetComponent<Animator> ();
}

// Update is called once per frame
void OnTriggerStay(Collider other) {

	if (Input.GetKeyDown (KeyCode.P)) {

		animator.SetBool ("stick", true);
		stick = true;
	}

	if (Input.GetKeyDown (KeyCode.O)) {
		animator.SetBool ("stick", false);
		stick = false;
	}


}

script for land gear:

public class landinggear : MonoBehaviour {

	private panel pan;
	private Animator anim;
	private GameObject player;

	// Use this for initialization
	void Start () {
	
		pan = GameObject.Find ("panel").GetComponent<panel> ();
	}
	
	// Update is called once per frame
	void Update () {
	
		if(pan.stick)
		{
			anim.SetBool("retraction",true);
		}

		if(!pan.stick)
		{
			anim.SetBool("retraction",false);
		}
	}
}

p/s: I still very confuse about using code to call upon checking for the control panel boolean is it true or false ( So saying that under landing gear script ; void update ; that part i not sure is it a correct way to check the boolean… ) ( really appreciate you guys can help… thanksss