How do I get the bounds of a rigidbody's compound collider?

How do I get the bounds of a rigidbody's compound collider?

I've looked through the Unity documentation and googled looking for the answer and couldn't find anything about this. If I need something like that, would most people just grab the bounds from "renderer.bounds"?

Thanks!

edit: I just realized this post may be in the wrong catagory, not sure though. Should I have asked this in Unity Answers? Or the scripting forum? Whoops, sorry!

 

Loop through the children and get their bounds, and add them all together.

--Eric

 

Thanks! 'Adding' might not have been the most accurate word. I first tried adding all the sizes together and realized that was inflating too much (interior colliders extending length). Looking at the documentation, 'Encapsulate' is what I needed to do. For anyone needing to do this in the future, the code is something like:

Code (csharp):

1.  
2.         Collider[] myColliders = GetComponentsInChildren<Collider> ();
3.         Bounds myBounds = new Bounds (transform.position , Vector3.zero);
4.         foreach (Collider nextCollider in myColliders)
5.         {
6.             myBounds.Encapsulate (nextCollider.bounds);
7.         }
8.         Debug.Log (myBounds);
9.  

The myBounds variable is printing out nicely to the console, and changing the rotation of the parent is increasing/decreasing the size of the AABB! Woot!

 

Indeed, Bounds.Encapsulate is what I was referring to; sorry for not being more specific. Glad you found it anyway.

--Eric

 

Since this answer is still valid 7 years later, I wanted to correct something:

If your colliders do not encapsulate the transform.position of your rigidbody, the solution above will not give the correct results. Here's a utility method that works even in that case:

Code (CSharp):

1.       public static Bounds GetCombinedBoundingBoxOfChildren(Transform root)
2.         {
3.             if (root == null)
4.             {
5.                 throw new ArgumentException("The supplied transform was null");
6.             }
7.  
8.             var colliders = root.GetComponentsInChildren<Collider>();
9.             if (colliders.Length == 0)
10.             {
11.                 throw new ArgumentException("The supplied transform " + root?.name + " does not have any children with colliders");
12.             }
13.  
14.             Bounds totalBBox = colliders[0].bounds;
15.             foreach (var collider in colliders)
16.             {
17.                 totalBBox.Encapsulate(collider.bounds);
18.             }
19.             return totalBBox;
20.         }