How do I make an array and then access an Object from the array

[ravendevil67]

here is the code that doesnt seem to work…

#pragma strict
#pragma implicit
#pragma downcast
 
var controllableObjects     : GameObject[];
 
var playerObject         : GameObject;
var playerCamTrans       : Transform;
var playerCamera         : GameObject;
 
var targetObject         : GameObject;
var targetCamera         : GameObject;
 
var canUse   = true;
var rayDepth    = 3;
 
// Reticle
var drawReticle = true;
var crosshairTexture    : Texture;
private var position    : Rect;
 
private var objCamera   : GameObject;
 
class ControlObjectManager extends MonoBehaviour
{
    function Start ()
    {
       Debug.Log("Start  : ");
       // Add the 'Player'
       playerObject  = GameObject.FindGameObjectWithTag("Player");
       Debug.Log("playerObject            : " + playerObject);
 
       playerCamera  = playerObject.transform.FindChild("MainCamera").gameObject;
       Debug.Log("playerCamera  : " + playerCamera);
 
       controllableObjects   = GameObject.FindGameObjectsWithTag("ControllableObject");
 
        // iterate through the array
        for (var obj in controllableObjects)
        {
            if (obj.tag == "ControllableObject")
            {
          objCamera = obj.transform.FindChild("MainCamera").gameObject;
          Debug.Log("Turning Off Camera  : " + objCamera);
          objCamera.camera.depth = 1;
               objCamera.camera.active = false;
            }
        }
 
       // Reticle
       position = Rect((Screen.width - crosshairTexture.width) / 2,
                   (Screen.height - crosshairTexture.height) / 2,
                    crosshairTexture.width, crosshairTexture.height);
 
       // Mouse Cursor
        Screen.lockCursor = true;
    }
 
    function Update ()
    {
       if (canUse && Input.GetButtonDown("Use"))
       {
         Debug.Log("Use Activated !");
 
         if (!targetObject)
         {
          var camX    = playerCamera.camera.GetScreenWidth() / 2;
          var camY    = playerCamera.camera.GetScreenHeight()    / 2;
 
          Debug.Log("playerObject    : " + playerObject);
          Debug.Log("From Camera     : " + playerCamera + "  ... Attached to GameObject  : " + playerCamera.transform.root);
 
          var hit: RaycastHit;
          var ray = playerCamera.camera.ScreenPointToRay (Vector3(camX, camY, rayDepth));
 
               if (Physics.Raycast(ray, hit) && hit.collider != null && hit.collider.gameObject.tag == "ControlTrigger")
          {
              Debug.Log("GameObject      : " + hit.collider.gameObject);
 
              playerObject.SendMessage ("SetControllable", false);
              playerCamera.camera.active = false;
              //playerCamera.camera.depth = 1;
 
              targetObject = hit.collider.gameObject.GetComponent(ControlTrigger).controlObject;
              Debug.Log("Target Object      : " + targetObject);
              targetObject.SendMessage ("SetControllable", true);
 
              targetCamera = targetObject.transform.FindChild("MainCamera").gameObject;
              Debug.Log("Target Camera      : " + targetCamera);
              targetCamera.camera.active = true;
              //targetCamera.camera.depth = 0;
          }
          else
          {
              Debug.Log("GameObject      : " + hit.collider.gameObject);
              targetObject = null;
          }
         }
         else
         {
          playerObject.SendMessage ("SetControllable", true);
          playerCamera.camera.active = true;
          //playerCamera.camera.depth = 0;
 
          targetObject.SendMessage ("SetControllable", false);
 
          //targetCamera.camera.depth = 1;
          targetCamera.camera.active = false;
         }
       }
    }
 
    function OnGUI()
    {
       // Draw Reticle
       if(drawReticle)
       {
         GUI.DrawTexture(position, crosshairTexture);
       }
    }
}

error :

NullReferenceException
UnityEngine.Component.get_gameObject () (at C:/BuildAgent/work/7535de4ca26c26ac/Runtime/ExportGenerated/Editor/UnityEngineComponent.cs:170)
ControlObjectManager.Start () (at Assets/Assets/Scripts/ControlManager/ControlObjectManager.js:34)

[iwaldrop]

It looks like you’re doing everything right as far as the code goes. You just have a null reference, so that means that something is not being found. You seem to know where your errors are, so that should narrow down your problem quite a bit.

If I were debugging this, I’d first make sure that there is a GameObject called MainCamera childed to “Player”.

But since I’m not, I’d also suggest creating a public field in your script for you to just drag the camera onto the inspector, like so:

    public Camera playerCamera;

Now checkout the inspector for your Player, and you should see the field. Drag in the camera, and test it.

For your “ControllableObjects” problem, you probably can’t just drag in a bunch of references, because, I assume, they’re always changing. Again, it seems like the problem is that your gameObject doesn’t have a child named “MainCamera”. There really isn’t anything else in your code to go wrong at that point.

[ravendevil67]

Nevermind, I fixed it. Thank you though…

var canUse						: boolean	= true;
private	var controllableObjects	: GameObject[];
private	var playerObject		: GameObject;
private	var playerCamera		: GameObject;
private	var targetObject		: GameObject;
private	var targetCamera		: GameObject;
var rayDepth					: float		= 3;

class ControlObjectManager extends MonoBehaviour
{
    function Start ()
    {
		// Add the 'Player'
		playerObject = GameObject.FindGameObjectWithTag("Player").gameObject;
		playerCamera = GetChildByTag(playerObject, "Camera", "MainCamera");
		
		controllableObjects   = GameObject.FindGameObjectsWithTag("ControllableObject");
		
		// iterate through the array
		for (var obj in controllableObjects)
		{
			if (obj.tag == "ControllableObject")
			{
				obj.SendMessage ("SetControllable", false);
				var objCamera : GameObject = GetChildByTag(obj, "Camera", "MainCamera");
				
				if (objCamera)
				{
					objCamera.camera.depth = 1;
					objCamera.camera.active = false;
				}
				else Debug.Log("No Camera Attached To : " + obj + " : Tagged : " + "MainCamera");
			}
		}
	}
	
	function Update ()
	{
		if (canUse && Input.GetButtonDown("Use"))
		{
			//Debug.Log("Use Activated !");
			
			if (!targetObject)
			{
				var camX    = playerCamera.camera.GetScreenWidth()	/ 2;
				var camY    = playerCamera.camera.GetScreenHeight()	/ 2;
				
				var hit: RaycastHit;
				var ray = playerCamera.camera.ScreenPointToRay (Vector3(camX, camY, rayDepth));
				
				if (Physics.Raycast(ray, hit) && hit.collider != null && hit.collider.gameObject.tag == "ControlTrigger")
				{
					playerObject.SendMessage ("SetControllable", false);
					playerCamera.camera.active = false;
					playerCamera.camera.depth = 1;
					
					targetObject = hit.collider.gameObject.GetComponent(ControlTrigger).controlObject;
					targetObject.SendMessage ("SetControllable", true);
					
					targetCamera = GetChildByTag(targetObject, "Camera", "MainCamera");
					targetCamera.camera.active = true;
					targetCamera.camera.depth = 0;
				}
				else
				{
					targetObject = null;
				}
			}
			else
			{
				playerObject.SendMessage ("SetControllable", true);
				playerCamera.camera.active = true;
				playerCamera.camera.depth = 0;
				
				targetObject.SendMessage ("SetControllable", false);
				
				targetCamera.camera.depth = 1;
				targetCamera.camera.active = false;
				targetObject = null;
			}
		}
	}
	
	function GetChildByTag(searchObj:GameObject, withType:String, withTag:String)
	{
		switch (withType)
		{
			case "GameObject" :
				var childObjects = searchObj.transform.GetComponentsInChildren(GameObject, true);
				
				// iterate through the array
				for (var obj in childObjects)
				{
					if (obj.gameObject.tag == withTag) return obj.gameObject;
				}
			break;
		
			
			case "Camera" :
				var childCameras = searchObj.transform.GetComponentsInChildren(Camera, true);
				
				// iterate through the array
				for (var cam in childCameras)
				{
					if (cam.gameObject.tag == withTag) return cam.gameObject;
				}
			break;
		}
	}
}