Why is the Controller Returning Null Reference Exception?

In the Console it Says:
NullReferenceException: Object reference not set to an instance of an object
ExtinguisherJet.Bursting () (at Assets/Scripts/ExtinguisherJet.cs:76)
ExtinguisherJet.Update () (at Assets/Scripts/ExtinguisherJet.cs:113)

Note: This is the line where I set It to work with the Oculus Touch (Oculus Rift's Controller). But with the B key I've set to the Keyboard It does not return any error and works perfectly.

Note2: I'm Using SteamVR.

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class ExtinguisherJet : MonoBehaviour
6. {
7.     private SteamVR_Controller.Device controller;
8.     private Transform heldObj;
9.     private GameObject jet;
10.     private Animator anim;
11.     [SerializeField] private GameObject[] extrs;
12.     [SerializeField] private Transform fbHand;
13.     private string lasMessage;
14.     private bool lookForExtinguisher ()
15.     {
16.         bool isThere = false;
17.  
18.         try
19.         {
20.             heldObj = fbHand.transform.GetChild(2);
21.             isThere = true;
22.         }
23.         catch (System.Exception e)
24.         {
25.             heldObj = null;
26.             isThere = false;
27.         }
28.         return isThere;
29.     }
30.     //--------------------------------------------//
31.  
32.     void Start()
33.     {
34.         lasMessage = "";
35.         jet = null;
36.         anim = null;
37.     }
38.  
39.     private void CheckHand ()
40.     {
41.         if (lookForExtinguisher () && lasMessage != heldObj.name)  // lasMessage is Just to Keep the console from printing the same stuff over and over
42.         {
43.             print ("Yo, check It out, I got some" + " " + heldObj.name);
44.  
45.             if (heldObj.name == "Extinguisher")
46.             {
47.                 jet = heldObj.gameObject;
48.                 for (int i = 1; i < 20; i++)
49.                     jet = jet.transform.GetChild(0).gameObject;
50.  
51.                 print ("Found " + jet.name + " in " + heldObj.name);
52.                 anim = heldObj.GetComponent <Animator>();
53.                 anim.SetBool ("willAim", true);
54.             }
55.  
56.             lasMessage = heldObj.name;
57.  
58.         } else if (!lookForExtinguisher () && lasMessage != "nothing") {
59.             print ("Ma boey! Derr's nothin' on yo hands!");
60.             lasMessage = "nothing";
61.  
62.             if (anim != null)
63.                 anim.SetBool("willAim", false);
64.         }
65.     }
66.  
67.     private void Bursting ()
68.     {
69.         if (lookForExtinguisher ())
70.         {
71.             if (heldObj.name == "Extinguisher" && Input.GetKey(KeyCode.B))
72.             {
73.                 print ("I'm Bursting");
74.                 jet.SetActive (true);
75.             }
76.             else if (heldObj.name == "Extinguisher" && controller.GetPressDown(SteamVR_Controller.ButtonMask.Trigger))
77.             {
78.                 print ("I'm Bursting");
79.                 jet.SetActive(true);
80.             }
81.             else if (jet != null)
82.             {
83.                 jet.SetActive(false);
84.             }
85.         }
86.     }
87.  
88.     private void SearchforBursting ()
89.     {
90.         GameObject tempObj = null;
91.         GameObject tempJt = null;
92.         int i = 0;
93.         int j = 0;
94.         for (i = 0; i < extrs.Length; i++)
95.         {
96.             tempObj = extrs [i];
97.             tempJt = tempObj;
98.             for (j = 1; j < 20; j++)
99.                 tempJt = tempJt.transform.GetChild(0).gameObject;
100.            
101.             if (tempJt.activeSelf && heldObj != tempObj.transform)
102.             {
103.                 tempJt.SetActive(false);
104.                 print ("Deactivated");
105.                 print (heldObj + ", " + tempObj);
106.             }
107.         }
108.     }
109.  
110.     void Update ()
111.     {
112.         CheckHand ();
113.         Bursting ();
114.         SearchforBursting ();
115.     }
116. }

Thanks;
Arthur.

 

Then my guess is controller is null. I don't see you assigning anything to it in this script.

 

What you mean? It serves to print "bursting" and activating the jet, just like It's done to the KeyCode.B Above it

 

Have you tried putting a breakpoint on line 76 to see which variable is null? That might be a good starting point to work from.

 

Brea

Breakpoint? What is that?

 

Are you using monodevelop or Visual Studio?

 

monodevelop

 

You seem pretty new to programming...

Code (CSharp):

1. private SteamVR_Controller.Device controller;

This line creates a variable.

But you never assign anything to it, which makes it null.

Code (CSharp):

1.  controller.GetPressDown(SteamVR_Controller.ButtonMask.Trigger)

So when you call this line, you get a null reference error. controller has no value. It's null.

Where do you assign something to controller?

controller = something

 

In that case, you may want to directly consider the suggestion by Brathnann which would seem to be the answer you are looking for.

I would, however, recommend moving over to Visual Studio. The debugger is exceptionally useful and would have shown you to the solution here very quickly.

This is because the code flow does not reach the offending line in that case.