Iterating through RaycastHit2D[] to find highest transform.y?

Question

Hi all,

This question betrays me as a beginner. I am currently trying to do something relatively simple - I am using RaycastAll to return an array of hit, and I then wish to select the hit that contains the collider with the greatest transform.position.y value (and that also is tagged with the value "Node"). The following code accomplishes this:

 RaycastHit2D[] hits = Physics2D.RaycastAll(Camera.main.ScreenToWorldPoint(Input.mousePosition), Vector2.zero);
 RaycastHit2D selectedHit = hits[0];
 bool hitSelected = false;
 foreach (var hit in hits)
 {
     if (hit.collider != null)
     {
         if (hit.collider.tag == "Node")
         {
                 if (!hitSelected)
             {
                 selectedHit = hit;
                 hitSelected = true;
             } else
             {
                 if (hit.collider.transform.position.y > selectedHit.transform.position.y)
                 {
                     selectedHit = hit;
                 }
             }
                         
         }
     }
 }

However, I can't help but feel that this is a bit hackish. Is there a cleaner, more acceptable way of accomplishing this?

Answer 1

Best Answer

Answer by Hellium · Oct 26, 2020 at 10:32 PM

 // Consider storing `Camera.main` into a variable you initialize in the `Start` method
 RaycastHit2D[] hits = Physics2D.RaycastAll(Camera.main.ScreenToWorldPoint(Input.mousePosition), Vector2.zero);
 RaycastHit2D? selectedHit = null;
 
 foreach (var hit in hits)
 {
     Collider collider = hit.collider;
     if (collider != null && collider.CompareTag("Node"))
     {
         if (selectedHit.HasValue == false || collider.transform.position.y > selectedHit.Value.transform.position.y)
         {
             selectedHit = hit;
         }
     }
 }

 // Consider storing `Camera.main` into a variable you initialize in the `Start` method
 RaycastHit2D[] hits = Physics2D.RaycastAll(Camera.main.ScreenToWorldPoint(Input.mousePosition), Vector2.zero);
 if(hits.Length > 0)
 {
     RaycastHit2D selectedHit = hits[0];
 
     for(int i = 1 ; i < hits.Length ; ++i)
     {
         Collider collider = hits[i].collider;
         if (collider != null && collider.CompareTag("Node") && collider.transform.position.y > selectedHit.transform.position.y)
         {
             selectedHit = hits[i];
         }
     }
 }

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jamesleakos · Oct 26, 2020 at 10:47 PM 0

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So I did try something similar to this at first, but it doesn't allow selectedHit to be assigned as null, which is why I had to hack out that other solution with the bool.

Hellium jamesleakos · Oct 26, 2020 at 11:12 PM 0

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Right, I forgot RaycastHit2D is a struct and not a class. I've updated my answer and used a Nullable RaycastHit2D (code not tested though)

I've also added another possible solution

Iterating through RaycastHit2D[] to find highest transform.y?

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