Selection Management c#

Here I have been trying to create a selection management so that at any given time there will be only one gameobject selected or highlighted. I have done my utmost and here I have put the script. The thing is, i cant seem to alternate selections and I often get a "NullReferene". The script is partly working and partly not. Can you help me out? I need to know how to get thing done.

Code (CSharp):

1.  
2. using UnityEngine;
3. using System.Collections;
4.  
5. public class MouseControl1 : MonoBehaviour {
6.     //This scripts handles the actions performed by the mouse
7.  
8.     public GameObject currentlyselected;
9.     public bool selected = false;
10.     public RaycastHit hit;
11.  
12.     public void Start ()
13.     {
14.  
15.     }
16.  
17.     public void Update()
18.     {
19.         MouseController();
20.     }
21.  
22.     //This funcition controls the actions performed by the mouse
23.     public void MouseController()
24.     {
25.         //if the left mouse button is down
26.         if(Input.GetMouseButtonDown(0))
27.         {
28.             //Player pressed the mousebutton
29.             Debug.Log ("Player pressed the mousebutton.");
30.             //cast a ray into the scene to detect objects
31.             Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
32.             if(Physics.Raycast(ray, out hit, Mathf.Infinity))
33.             {
34.                 //print the name of the object the ray collided
35.                 Debug.Log(hit.transform.gameObject.name);
36.             }
37.  
38.             //if the ray hits a player
39.             if(hit.transform.gameObject.tag == "Player")
40.             {
41.                 currentlyselected = hit.transform.gameObject;
42.                 Select();
43.                 Debug.Log(1);
44.             } else {
45.                 if(selected == true)
46.                 {
47.                     Deselect();
48.                     currentlyselected = hit.transform.gameObject;
49.                     Select();
50.                     Debug.Log(2);
51.                 }
52.             }
53.  
54.             //if the ray doesn't hit the player and the object is selected
55.             if(hit.transform.gameObject.tag != "Player" && selected == true)
56.             {
57.                 Deselect();
58.                 Debug.Log(3);
59.             } else {
60.                 if(selected != true)
61.                 {
62.                     Debug.Log("There was nothing there.");
63.                     Debug.Log(4);
64.                 }
65.             }
66.         }
67.     }
68.  
69.     public void Select()
70.     {
71.         currentlyselected.transform.FindChild("Blob Light Projector").gameObject.SetActive(true);
72.         selected = true;
73.     }
74.  
75.     public void Deselect()
76.     {
77.         currentlyselected.transform.FindChild("Blob Light Projector").gameObject.SetActive(false);
78.         currentlyselected = null;
79.         selected = false;
80.     }
81.  
82. }
83.  

 

What is line number where you gon an error?

I see couple of danger strokes:

Code (csharp):

1. currentlyselected.transform.FindChild("Blob Light Projector").gameObject.SetActive(true)

It will give you an NullRef exception in case when "Blob Light Projector" object is not exist.
This is more safety code style:

Code (csharp):

1. var go = currentlyselected.transform.FindChild("Blob Light Projector");
2. if(go!= null)
3.    go.gameObject.SetActive(true);
4. else
5.    Debug.Log("'Blob Light Projector' was not found among children of '"+currentlyselected.Name+"'");

 

I'm thinking you have to put the lines 38 to 65 also into the if clause which starts at line 32. It should look like this:

Code (CSharp):

1.            
2.             if(Physics.Raycast(ray, out hit, Mathf.Infinity))
3.             {
4.                 //print the name of the object the ray collided
5.                 Debug.Log(hit.transform.gameObject.name);
6.                 //if the ray hits a player
7.                 if(hit.transform.gameObject.tag == "Player")
8.                 {
9.                     currentlyselected = hit.transform.gameObject;
10.                     Select();
11.                     Debug.Log(1);
12.                 } else {
13.                     if(selected == true)
14.                     {
15.                         Deselect();
16.                         currentlyselected = hit.transform.gameObject;
17.                         Select();
18.                         Debug.Log(2);
19.                     }
20.                 }
21.    
22.                 //if the ray doesn't hit the player and the object is selected
23.                 if(hit.transform.gameObject.tag != "Player" && selected == true)
24.                 {
25.                     Deselect();
26.                     Debug.Log(3);
27.                 } else {
28.                     if(selected != true)
29.                     {
30.                         Debug.Log("There was nothing there.");
31.                         Debug.Log(4);
32.                     }
33.                 }
34.             }            
35.  

Otherwise you check in your if statements for the tags of the gameobjects, but the ray hasn't hit something.

 

Well that does make sense but I think I will try what patico recommended. After posting this question in the forum even his solution occurred to me.

 

Cheers mate! I will give this a try...