Instantiate + force on click

Unity Engine
1

So ive got this game where i shoot an “arrow” at an object. Right now, its just a long cube attached to the camera. I use a rigid body (no gravity) that is in the center of the camera. When you click, its forced foward, and using some code i found here, sticks to the object and detach itself from the parent. The problem is that i can only shoot it once.

previous attempts have caused too many cubes to instantiate. So im wondering how i could Instantiate an “arrow” from an empty game object and force it forward on click, and also stop any new arrows from reacting to the click

so far ive got this attached to my arrow.

unction Update () {
	var click : float = Input.GetAxis("Fire1");
	var power : float = 200;
	
		rigidbody.AddForce(Vector3(0,0,click * power));
	
		
	}
2

Does this help? Attach it to your camera / whatever fires arrows, set the arrow and power vars in the inspector.

var arrow : GameObject;
var power : float;

function Update() {
  if ( Input.GetKeyDown( KeyCode.Mouse0 ) ) {
    var anArrow = Instantiate( arrow, transform.position, transform.rotation );
    anArrow.rigidbody.AddForce( transform.forward * power );
  }
}
3

var arrow would be where i stick the arrow?

4

I am typing this in the Quick Reply, so just pseudo code this time.

Put this on your Player or his Bow

//outside update
gameobject Arrow; // put the Arrow Prefab here
gameobject currentArrow = null;


// inside update
if(Input.GetButtonDown("Fire1"))
{
// Basicly when the FireButton is Clicked Down, instantiate an Arrow Object at the Bow.
currentArrow = Instantiate(Arrow, transform.position, transform.rotation);
}
else if ( Input.GetButtonUp("Fire1"))
{
// Check if the User has released the fire Button, and set the flying property on the arrow
// This would also be the place where you can calculate the Power, based on how long the Fire1   // Button was held down

currentArrow.flying = true;
currentArrow = null; // We don't need a reference anymore.
}

Put this on the Arrow

// Outside Update

var power : float = 200;
bool flying = false;

// inside of Update
if ( flying )
{
// Do your acceleration Stuff here
rigidbody.AddForce(Vector3(0,0,power));

}

Hope that helps.

5

Yes that worked perfectly, thanks a bunch!

i am still applying force to the arrows though

6

Does the currentArrow bit stop the force from being applied later?

7

I see what you mean now.
More Pseudo Code:

Put this on your Bow, almost the same code

//outside update
gameobject Arrow; // put the Arrow Prefab here
gameobject currentArrow = null;


// inside update
if(Input.GetButtonDown("Fire1"))
{
// Basicly when the FireButton is Clicked Down, instantiate an Arrow Object at the Bow.
currentArrow = Instantiate(Arrow, transform.position, transform.rotation);
}
else if ( Input.GetButtonUp("Fire1"))
{
// Check if the User has released the fire Button, and call the Fire Function on the Arrow
// This would also be the place where you can calculate the Power, based on how long the Fire1   // Button was held down
// do your Power Calculation here
float power = 200;

// Afterwards call the Fire Function on the Arrow, normally you would also pass a direction Vector but I leave that up to you
currentArrow.Fire(power);
currentArrow = null; // We don't need a reference anymore.
}

// Put this on your Arrow

// Instead of using Update, we are going to define a fire function on the Arrow
// Remove the Update Function from before

// This will only be called once
function Fire( power: float )
{
       // The force will only be added once
       rigidbody.AddForce(Vector3(0,0,power));
}