Question by ajheschl · Apr 22, 2020 at 09:55 AM · instantiate 2d game bounds point endless runner

Instantiating randomly sized prefab to the right of another 2D

I am attempting to instantiate differently shaped prefabs next to eachother. I have a folder full of differently sized objects that allow for me to string them together randomly to create a 2D endless runner. My issue is that all the answers online about placing objects beside eachother don't work when different sized objects are used. Here is the code I am using to instantiate the sections. It works when it only randomly selects similar sized objects. When the selected prefab is a different length it leaves either a gap between, or overlaps, the previous object. The prefab objects have multiple children.

  for(int i = 0; i < activeSectionsAtOnce; i++)
  {
     int index = Random.Range(0, sectionPrefabs.Length);
     GameObject currentOb = sectionPrefabs[index];

     Vector2 position = new Vector2();
     if(activeSections.Count == 0)
     {
         //set a (0, 0) position for first object
         position = Vector2.zero;
     }
     else
     {
         //get most recently placed object from list
         GameObject lastOb = activeSections[activeSections.Count - 1];

         //my attempt at getting bounds for the last object and for the next prefab that will be used
         Bounds lasObbounds = new Bounds(lastOb.transform.position, Vector2.zero);
         Bounds currentBounds = new Bounds(currentOb.transform.position, Vector2.zero);

         //Include child objects(all have sprite renderers)
         foreach (Renderer r in lastOb.GetComponentsInChildren<Renderer>())
         {
             lasObbounds.Encapsulate(r.bounds);
         }
         foreach (Renderer rend in currentOb.GetComponentsInChildren<Renderer>())
         {
             currentBounds.Encapsulate(rend.bounds);
         }
         //position object will be instantiated at
         position.x = lastOb.transform.position.x + (lasObbounds.size.x / 2) + (currentBounds.size.x/2);
     }
     //instantiate at selected position
     activeSections.Add(
         Instantiate(currentOb, position, Quaternion.identity)
     );
 }

This is in the start method and in LateUpdate when I check if the sections are off the screen. I'm not sure if the problem is how I'm creating the bounds, or how im mathematicaly creating the x coordinate. This is the expected result that happens when I use same sized prefabs. alt text