diff --git a/src/collision/aabb.go b/src/collision/aabb.go
index 3d7cbd78..8b5dc5a6 100644
--- a/src/collision/aabb.go
+++ b/src/collision/aabb.go
@@ -67,20 +67,8 @@ func AABBFromMinMax(min, max matrix.Vec3) AABB {
 
 // Union returns the union of two AABBs
 func AABBUnion(a, b AABB) AABB {
-	aMin := a.Min()
-	aMax := a.Max()
-	bMin := b.Min()
-	bMax := b.Max()
-	min := matrix.Vec3{
-		matrix.Min(aMin.X(), bMin.X()),
-		matrix.Min(aMin.Y(), bMin.Y()),
-		matrix.Min(aMin.Z(), bMin.Z()),
-	}
-	max := matrix.Vec3{
-		matrix.Max(aMax.X(), bMax.X()),
-		matrix.Max(aMax.Y(), bMax.Y()),
-		matrix.Max(aMax.Z(), bMax.Z()),
-	}
+	min := matrix.Vec3Min(a.Min(), b.Min())
+	max := matrix.Vec3Max(a.Max(), b.Max())
 	return AABBFromMinMax(min, max)
 }
 
diff --git a/src/collision/bvh.go b/src/collision/bvh.go
index acc75c0a..5c817bc3 100644
--- a/src/collision/bvh.go
+++ b/src/collision/bvh.go
@@ -21,6 +21,14 @@ type BVH struct {
 
 func NewBVH() *BVH { return &BVH{} }
 
+func (b *BVH) Root() *BVH {
+	r := b
+	for r.Parent != nil {
+		r = r.Parent
+	}
+	return r
+}
+
 func (b *BVH) Bounds() AABB {
 	if b.Transform == nil {
 		return b.bounds
@@ -103,7 +111,7 @@ func BVHInsert(into, other *BVH) *BVH {
 		// root node to hold everything
 		if into.IsRoot() {
 			into.bounds = AABBUnion(ib, ob)
-			into.bounds.Extent.Scale(1.001)
+			into.bounds.Extent.ScaleAssign(1.001)
 			return BVHInsert(into, other)
 		} else {
 			bvh := &BVH{
@@ -173,10 +181,16 @@ func (b *BVH) RemoveNode() {
 		promote = parent.Right
 	}
 	if parent.IsRoot() {
-		*parent = *promote
-		parent.Parent = nil
-		parent.Left.Parent = parent
-		parent.Right.Parent = parent
+		if promote != nil {
+			*parent = *promote
+			parent.Parent = nil
+			parent.Left.Parent = parent
+			if parent.Right != nil {
+				parent.Right.Parent = parent
+			}
+		} else {
+			parent.Left = nil
+		}
 	} else {
 		if parent.IsLeft() {
 			parent.Parent.Left = promote
diff --git a/src/editor/content/content_opener/obj_opener.go b/src/editor/content/content_opener/obj_opener.go
index 138a5978..8a3e16cd 100644
--- a/src/editor/content/content_opener/obj_opener.go
+++ b/src/editor/content/content_opener/obj_opener.go
@@ -146,6 +146,7 @@ func (o ObjOpener) Open(adi asset_info.AssetDatabaseInfo, ed interfaces.Editor)
 	host.AddEntity(e)
 	e.SetName(adi.MetaValue("name"))
 	bvh := collision.NewBVH()
+	bvh.Transform = &e.Transform
 	for i := range adi.Children {
 		if err := load(host, adi.Children[i], e, bvh); err != nil {
 			return err
diff --git a/src/editor/editor.go b/src/editor/editor.go
index f768c013..6f6f870f 100644
--- a/src/editor/editor.go
+++ b/src/editor/editor.go
@@ -125,6 +125,20 @@ func (e *Editor) StatusBar() *status_bar.StatusBar      { return e.statusBar }
 func (e *Editor) Hierarchy() *hierarchy.Hierarchy       { return e.hierarchy }
 func (e *Editor) BVH() *collision.BVH                   { return e.bvh }
 
+func (e *Editor) BVHEntityUpdates(entities ...*engine.Entity) {
+	root := e.bvh
+	for _, e := range entities {
+		d := e.EditorBindings.Data("bvh")
+		if d == nil {
+			continue
+		}
+		bvh := d.(*collision.BVH)
+		bvh.RemoveNode()
+		root = collision.BVHInsert(root, bvh)
+	}
+	e.bvh = root
+}
+
 func (e *Editor) AvailableDataBindings() []codegen.GeneratedType {
 	return e.entityData
 }
@@ -279,8 +293,7 @@ func (e *Editor) Init() {
 		dc.(*rendering.OITCanvas).ClearColor = matrix.ColorTransparent()
 		ot.ClearColor = matrix.ColorTransparent()
 		e.overlayCanvas = ot
-		e.transformTool = transform_tools.New(e.Host(),
-			&e.selection, "editor_overlay", &e.history)
+		e.transformTool = transform_tools.New(e.Host(), e, "editor_overlay", &e.history)
 		e.selection.Changed.Add(func() {
 			e.transformTool.Disable()
 		})
diff --git a/src/editor/interfaces/editor.go b/src/editor/interfaces/editor.go
index 08c9d60c..4b8226ad 100644
--- a/src/editor/interfaces/editor.go
+++ b/src/editor/interfaces/editor.go
@@ -63,5 +63,7 @@ type Editor interface {
 	AvailableDataBindings() []codegen.GeneratedType
 	ReloadEntityDataListing()
 	CreateEntity(name string) *engine.Entity
+	// TODO:  BVH stuff can be encapsulated into another structure
 	BVH() *collision.BVH
+	BVHEntityUpdates(entities ...*engine.Entity)
 }
diff --git a/src/editor/viewport/tools/transform_tools/tool_history.go b/src/editor/viewport/tools/transform_tools/tool_history.go
index b1bf545f..43c24991 100644
--- a/src/editor/viewport/tools/transform_tools/tool_history.go
+++ b/src/editor/viewport/tools/transform_tools/tool_history.go
@@ -38,11 +38,13 @@
 package transform_tools
 
 import (
+	"kaiju/editor/interfaces"
 	"kaiju/engine"
 	"kaiju/matrix"
 )
 
 type toolHistory struct {
+	editor   interfaces.Editor
 	entities []*engine.Entity
 	from     []matrix.Vec3
 	to       []matrix.Vec3
@@ -59,6 +61,7 @@ func (h *toolHistory) Redo() {
 			e.Transform.SetScale(h.to[i])
 		}
 	}
+	h.editor.BVHEntityUpdates(h.editor.Selection().Entities()...)
 }
 
 func (h *toolHistory) Undo() {
@@ -71,6 +74,7 @@ func (h *toolHistory) Undo() {
 			e.Transform.SetScale(h.from[i])
 		}
 	}
+	h.editor.BVHEntityUpdates(h.editor.Selection().Entities()...)
 }
 
 func (h *toolHistory) Delete() {}
diff --git a/src/editor/viewport/tools/transform_tools/transform_tool.go b/src/editor/viewport/tools/transform_tools/transform_tool.go
index c75129a3..96288613 100644
--- a/src/editor/viewport/tools/transform_tools/transform_tool.go
+++ b/src/editor/viewport/tools/transform_tools/transform_tool.go
@@ -39,8 +39,8 @@ package transform_tools
 
 import (
 	"kaiju/assets"
+	"kaiju/editor/interfaces"
 	"kaiju/editor/memento"
-	"kaiju/editor/selection"
 	"kaiju/engine"
 	"kaiju/hid"
 	"kaiju/matrix"
@@ -49,7 +49,7 @@ import (
 )
 
 type TransformTool struct {
-	selection      *selection.Selection
+	editor         interfaces.Editor
 	axis           AxisState
 	state          ToolState
 	lastHit        matrix.Vec3
@@ -83,12 +83,12 @@ func (t *TransformTool) createWire(nameSuffix string, host *engine.Host,
 	}
 }
 
-func New(host *engine.Host, selection *selection.Selection,
+func New(host *engine.Host, editor interfaces.Editor,
 	canvas string, history *memento.History) TransformTool {
 
 	wt := matrix.NewTransform()
 	t := TransformTool{
-		selection:     selection,
+		editor:        editor,
 		wireTransform: &wt,
 		resets:        make([]matrix.Vec3, 0, 32),
 		history:       history,
@@ -129,7 +129,7 @@ func (t *TransformTool) Update(host *engine.Host) (busy bool) {
 func (t *TransformTool) Enable(state ToolState) {
 	for i := range t.wires {
 		t.wires[i].ShaderData.Deactivate()
-		t.wireTransform.SetPosition(t.selection.Center())
+		t.wireTransform.SetPosition(t.editor.Selection().Center())
 		t.transformDirty = 2
 	}
 	switch t.axis {
@@ -155,7 +155,7 @@ func (t *TransformTool) Disable() {
 }
 
 func (t *TransformTool) resetChange() {
-	all := t.selection.Entities()
+	all := t.editor.Selection().Entities()
 	for i := range t.resets {
 		if t.state == ToolStateMove {
 			all[i].Transform.SetPosition(t.resets[i])
@@ -170,7 +170,7 @@ func (t *TransformTool) resetChange() {
 
 func (t *TransformTool) updateResets() {
 	t.resets = t.resets[:0]
-	for _, e := range t.selection.Entities() {
+	for _, e := range t.editor.Selection().Entities() {
 		if t.state == ToolStateMove {
 			t.resets = append(t.resets, e.Transform.Position())
 		} else if t.state == ToolStateRotate {
@@ -182,7 +182,7 @@ func (t *TransformTool) updateResets() {
 }
 
 func (t *TransformTool) addHistory() {
-	all := t.selection.Entities()
+	all := t.editor.Selection().Entities()
 	to := make([]matrix.Vec3, len(all))
 	from := make([]matrix.Vec3, len(all))
 	for i, e := range all {
@@ -196,11 +196,13 @@ func (t *TransformTool) addHistory() {
 		}
 	}
 	t.history.Add(&toolHistory{
-		entities: slices.Clone(t.selection.Entities()),
+		editor:   t.editor,
+		entities: slices.Clone(t.editor.Selection().Entities()),
 		from:     from,
 		to:       to,
 		state:    t.state,
 	})
+	t.editor.BVHEntityUpdates(t.editor.Selection().Entities()...)
 }
 
 func (t *TransformTool) commitChange() {
@@ -231,7 +233,7 @@ func (t *TransformTool) checkKeyboard(kb *hid.Keyboard) {
 
 func (t *TransformTool) updateDrag(host *engine.Host) {
 	m := &host.Window.Mouse
-	center := t.selection.Center()
+	center := t.editor.Selection().Center()
 	nml := matrix.Vec3Forward()
 	r := host.Camera.RayCast(m.Position())
 	var df, db, dl, dr, du, dd matrix.Float = -1.0, -1.0, -1.0, -1.0, -1.0, -1.0
@@ -302,7 +304,7 @@ func (t *TransformTool) updateDrag(host *engine.Host) {
 func (t *TransformTool) transform(delta, point matrix.Vec3, snap bool) {
 	// TODO:  Move this to configuration
 	const snapScale = 0.5
-	for i, e := range t.selection.Entities() {
+	for i, e := range t.editor.Selection().Entities() {
 		et := &e.Transform
 		if t.state == ToolStateMove {
 			d := t.resets[i].Subtract(t.wireTransform.Position())