How to make my character choose the closest object in range?

So I'm making a Sonic fangame and when pressing the Y button, i need to make sonic go through a series of rings. Everything works perfectly except for the fact that on button press Sonic goes to the furthest ring in range.
I tried adding some code I found to sort lists but it seems like it doesn't do much. Would you be so kind as to take a look at this snippet of code and telling me what I'm doing wrong? Thanks!

Code (CSharp):

1.  foreach (var ringy in rings)
2.             {
3.                 if (ringy != null)
4.                 {
5.                     if ((this.transform.position - ringy.transform.position).magnitude < lighDashDistance)
6.                     {
7.                         directionToRing = ringy.transform.position - transform.position;
8.                         float dSqrToRingy = directionToRing.sqrMagnitude;
9.                         if (Mathf.Infinity > dSqrToRingy)
10.                         {
11.                             nearRing = ringy;
12.                             YButtonDown = false;
13.  
14.                             animator.SetBool("isHoming", true);
15.                             GetComponent<lightDash>().enabled = true;
16.                             YButtonDown = false;
17.                             lightDashed = true;
18.  
19.                             this.enabled = false;
20.                             return;
21.  
22.                         }
23.  
24.  
25.                     }
26.                 }
27.             }

 

This doesn't look like it's performing any sorting, are you sure that you implemented the correct snippet?

Usually, to sort the rings and do something with the nearest ring, you would go through the whole list, keeping track of the currently closest ring and performing actions afterward:

Code (CSharp):

1. Ring nearestRing = null;
2. float minRingDistance = Mathf.Infinity;
3.  
4. // Find the nearest ring
5. foreach (var ringy in rings)
6. {
7.     float currentDistance = (ringy.transform.position - transform.position).magnitude;
8.     // Check if this ring is nearer that the previously nearest ring
9.     if (currentDistance < minRingDistance && currentDistance <= lightDashDistance)
10.     {
11.         nearestRing = ringy;
12.         minRingDistance = currentDistance;
13.     }
14. }
15.  
16. if (nearestRing != null)
17. {
18.     // Do something
19. }

 

note that if you are just comparing distance you may want to use Vector3.sqrMagnitude instead of Vector3.magnitude which is faster. It will be more obvious when dealing with more objects and do it frequently.

 

So I wrote this but it's still targeting the furthest ring in range. And the movement part of the script doesn't even work anymore (it uses pretty much the same system, but in Update instead of on button press. Also if I pick up a ring and press the button, I'm stuck in place and can't move and it gives me an error in the console
This is the error: "Missing Reference Exception: The object of type 'GameObject' has been destroyed but you are still trying to access it.
Your script should either check if it is null or you should not destroy the object."


Here's the code that you suggested:

Code (CSharp):

1.             foreach (var ringy in rings)
2.             {
3.  
4.                 float currentDistance = (ringy.transform.position - transform.position).magnitude;
5.  
6.  
7.        
8.  
9.                 if (currentDistance < minRingDistance && currentDistance <= lighDashDistance)
10.                 {
11.                     nearRing = ringy;
12.                     YButtonDown = false;
13.  
14.                     animator.SetBool("isHoming", true);
15.                     GetComponent<lightDash>().enabled = true;
16.                     YButtonDown = false;
17.                     lightDashed = true;
18.  
19.                     this.enabled = false;
20.                     return;
21.                 }
22.  
23.                 else
24.                 {
25.                     nearRing = null;
26.                 }
27.  
28.  
29.  
30.            }
31.  

 

My bad, erased on accident the check for nul. duh. So it still picks the furthest ring in range and after picking up a single ring, the action stops instead of going for the next one. Going to try and figure out what's happening.

EDIT: sorted it out, but again, this code does exactly the same thing (albeit cleaner, that's for sure)
that the old code.

 

This saves the closest ring in nearRing or Null if there is no ring.

 

Do I have to reset the

float shortestDistance

for every activation of the script?

 

Code (CSharp):

1.  
2. public ring getClosestRingWithinXDistance (List<ring>rings ,float minRingDistance)
3. {
4.     float shortestDistance=99999999;
5.     float currentDistance;
6.     ring nearRing;
7.             foreach (var ringy in rings)
8.                 {
9.  
10.                      currentDistance = (ringy.transform.position - transform.position).magnitude;
11.  
12.  
13.      
14.  
15.                     if (currentDistance < minRingDistance && currentDistance <= shortestDistance)
16.                     {
17.                         shortestDistance = currentDistance;
18.                         nearRing = ringy;
19.                     }
20.                   }
21. return nearRing;
22. }
23.