diff --git a/Source/Engine/Level/Actors/BoxCollider.cs b/Source/Engine/Level/Actors/BoxCollider.cs
deleted file mode 100644
index cfb6e9dde..000000000
--- a/Source/Engine/Level/Actors/BoxCollider.cs
+++ /dev/null
@@ -1,56 +0,0 @@
-#if FLAX_EDITOR
-using FlaxEditor.CustomEditors;
-using FlaxEditor.CustomEditors.Dedicated;
-#endif
-
-namespace FlaxEngine
-{
-    partial class BoxCollider
-    {
-        private void BoxExcluding(Actor target, ref BoundingBox output, Actor excluded)
-        {
-            foreach (Actor child in target.Children)
-            {
-                if (child == excluded)
-                {
-                    continue;
-                }
-
-                output = BoundingBox.Merge(output, child.Box);
-                BoxExcluding(child, ref output, excluded);
-            }
-        }
-
-        /// <summary>
-        /// Resizes the box collider based on the bounds of it's parent.
-        /// </summary>
-        public void AutoResize()
-        {
-            if (Parent is Scene)
-            {
-                return;
-            }
-
-            LocalPosition = Vector3.Zero;
-
-            Vector3 parentScale = Parent.Scale;
-            BoundingBox parentBox = Parent.Box;
-            BoxExcluding(Parent, ref parentBox, this);
-
-            Vector3 parentSize = parentBox.Size;
-            Vector3 parentCenter = parentBox.Center - Parent.Position;
-
-            // Avoid division by zero
-            if (parentScale.X == 0 || parentScale.Y == 0 || parentScale.Z == 0)
-            {
-                return;
-            }
-
-            Size = parentSize / parentScale;
-            Center = parentCenter / parentScale;
-
-            // Undo Rotation
-            Orientation *= Quaternion.Invert(Orientation);
-        }
-    }
-}
diff --git a/Source/Engine/Physics/Colliders/BoxCollider.cpp b/Source/Engine/Physics/Colliders/BoxCollider.cpp
index b80b68de0..d74b3efba 100644
--- a/Source/Engine/Physics/Colliders/BoxCollider.cpp
+++ b/Source/Engine/Physics/Colliders/BoxCollider.cpp
@@ -2,6 +2,7 @@
 
 #include "BoxCollider.h"
 #include "Engine/Physics/PhysicsBackend.h"
+#include "Engine/Level/Scene/Scene.h"
 
 BoxCollider::BoxCollider(const SpawnParams& params)
     : Collider(params)
@@ -19,6 +20,32 @@ void BoxCollider::SetSize(const Float3& value)
     UpdateBounds();
 }
 
+void BoxCollider::AutoResize()
+{
+    Actor* parent = GetParent();
+    if (Cast<Scene>(parent))
+        return;
+
+    // Get bounds of all siblings (excluding itself)
+    const Vector3 parentScale = parent->GetScale();
+    if (parentScale.IsAnyZero())
+        return; // Avoid division by zero
+    BoundingBox parentBox = parent->GetBox();
+    for (const Actor* sibling : parent->Children)
+    {
+        if (sibling != this)
+            BoundingBox::Merge(parentBox, sibling->GetBoxWithChildren(), parentBox);
+    }
+    const Vector3 parentSize = parentBox.GetSize();
+    const Vector3 parentCenter = parentBox.GetCenter() - parent->GetPosition();
+
+    // Update bounds
+    SetLocalPosition(Vector3::Zero);
+    SetSize(parentSize / parentScale);
+    SetCenter(parentCenter / parentScale);
+    SetOrientation(GetOrientation() * Quaternion::Invert(GetOrientation()));
+}
+
 #if USE_EDITOR
 
 #include "Engine/Debug/DebugDraw.h"
diff --git a/Source/Engine/Physics/Colliders/BoxCollider.h b/Source/Engine/Physics/Colliders/BoxCollider.h
index 5bcc21b45..3c15ce640 100644
--- a/Source/Engine/Physics/Colliders/BoxCollider.h
+++ b/Source/Engine/Physics/Colliders/BoxCollider.h
@@ -43,6 +43,11 @@ public:
         return _bounds;
     }
 
+    /// <summary>
+    /// Resizes the collider based on the bounds of it's parent to contain it whole (including any siblings).
+    /// </summary>
+    API_FUNCTION() void AutoResize();
+
 public:
     // [Collider]
 #if USE_EDITOR