Making a projectile specific model/mesh/etc rather than a primitive

Questions & Answers
1

Hey everyone, I just started using Unity yesterday so please overlook my ignorance over the next few weeks :slight_smile:

Basically, I have the following code that, after pressing the mouse, shoots a projectile from the camera to the mouse click’s location (ignore the “print” commands, they’re just bug testing) :

function Start () {
}

function Update () {
 if (Input.GetButtonDown ("Fire1")) {
 print("foobar");     
 var ray : Ray = camera.ScreenPointToRay (Input.mousePosition);
 print(ray);
 var sphere : GameObject = GameObject.CreatePrimitive(PrimitiveType.Sphere);
 print(sphere);
 sphere.transform.position = ray.origin;
 sphere.AddComponent("Rigidbody");
 sphere.transform.localScale += Vector3(.5, .5, .5);
 sphere.rigidbody.AddForce (ray.direction * 2000);
 }
}

As it stands, I create a primitive sphere that shoots out and collides with various items. What I want, however, is to use a custom-made model (an arrow). After importing my arrow into Unity how do I change the shot object from being a sphere to being that arrow?

2

Instantiation is what you are looking for:

BTW, this line

var sphere : GameObject = GameObject.print(sphere);

looks weird to me. You declare a sphere var and right after you use that.

3

whoops, accidentally pasted the same line twice. I edited it. Thanks for the correction. I’ll look into Instantiation.

4
  • put your arrow in the scene, add it rigidbody,
  • in asset create new prefab add it your arrow , drag from hierarchies, then delete arrow from scene/hierarchies
  • if fly bad remember the z axis is forward
    if have bad collision remove mesh collider and add a capsule collider

then use the prefab you have create from arrow as bullet remember to give rigidbody at the arrow

5

The answer to this issue is as follows:

  1. In the beginning of the script where you want to instantiate a prefab, write:
    var prefabClone : GameObject;

  2. The part of the script where you want to instantiate that prefab clone, write:
    var arrow = Instantiate(prefabClone, transform.position, transform.rotation );

  3. Attach the script to something. In my case, since I wanted to have an arrow shoot from my camera, so I attached it to my camera.

  4. Open the GameObject with the attached script in the hierarchy tab. Look at its inspector on the right pane. Notice that if you expand the script area (in my case, the “shooter” script that I attached, you see an empty gameObject that is the variable you defined at the beginning of the script (in my case, “prefabClone”).

  5. Assuming you have the prefab titled “prefabClone” already created in the Project tab, drag it from that tab to the inspector, on top of the empty GameObject in the script you created.

  6. Congrats! You’re done! The only issue with my code is the local rotation - if the camera moves, the projectile still tries to orient to the previous camera viewing angle (if I turn around in-game, the arrow will appear to be oriented backwards as it fires forward).

My code:

var arrowshoot : GameObject;

/* one, two, skip a few methods */

function Update () {

if (Input.GetButtonDown (“Fire1”)) {
var ray : Ray = camera.ScreenPointToRay (Input.mousePosition);
print(ray);
var sphere = Instantiate(arrowshoot, transform.position, transform.rotation );
sphere.transform.position = ray.origin;
sphere.transform.localScale += Vector3(.5, .5, .5);
sphere.transform.localRotation.x = 1;
sphere.rigidbody.AddForce (ray.direction * 5000);
}
}