fix(studio): Add solid floor collision, live 3D gizmo dragging, inspector property sync, and nudge shortcuts

scripts/studio/studio_main.gd

@@ -56,6 +56,18 @@ var _world_container: Node3D
 var _gizmo_3d: Node3D
 var _baseplate_mesh: MeshInstance3D
 
+# Drag & Drop / Transformation Interaction State
+var _is_dragging: bool = false
+var _drag_axis: int = 0
+var _drag_start_mouse: Vector2 = Vector2.ZERO
+var _drag_start_ground: Vector3 = Vector3.ZERO
+var _drag_start_node_pos: Vector3 = Vector3.ZERO
+var _drag_start_node_rot_deg: Vector3 = Vector3.ZERO
+var _drag_start_node_scale: Vector3 = Vector3.ONE
+var _drag_accum_y: float = 0.0
+var _drag_accum_rot: float = 0.0
+var _drag_accum_scale: float = 0.0
+
 # Docks & Dialogs
 var _hierarchy_dock = null
 var _inspector_dock = null
@@ -140,6 +152,7 @@ func _build_studio_layout() -> void:
 	left_panel.size_flags_vertical = Control.SIZE_EXPAND_FILL
 	_hierarchy_dock = StudioHierarchyDockClass.new()
 	_hierarchy_dock.setup(core)
+	_hierarchy_dock.delete_requested.connect(_delete_selected_object)
 	left_panel.add_child(_hierarchy_dock)
 	workspace_hbox.add_child(left_panel)
 
@@ -168,6 +181,8 @@ func _build_studio_layout() -> void:
 
 	_inspector_dock = StudioInspectorDockClass.new()
 	_inspector_dock.setup(core)
+	_inspector_dock.property_changed.connect(_on_inspector_property_changed)
+	_inspector_dock.delete_requested.connect(_delete_selected_object)
 	tabs.add_child(_inspector_dock)
 	tabs.set_tab_title(0, "Inspector")
 
@@ -306,7 +321,7 @@ func _build_toolbar(parent: Control) -> void:
 	_toolbar.add_child(snap_lbl)
 
 	_snap_spin = SpinBox.new()
-	_snap_spin.min_value = 0.1
+	_snap_spin.min_value = 0.5
 	_snap_spin.max_value = 10.0
 	_snap_spin.step = 0.5
 	_snap_spin.value = 1.0
@@ -393,13 +408,15 @@ func _quick_insert(cat_id: String, display_name: String) -> void:
 	if _camera_3d != null:
 		spawn_pos = _camera_3d.focal_point
 		spawn_pos.y = 0.0
-	var new_id := core.place_object(cat_id, spawn_pos, Vector4(0, 0, 0, 1), Vector3.ONE, {
+	var chunk_pos := _godot_to_chunk_pos(spawn_pos)
+	var new_id := core.place_object(cat_id, chunk_pos, Vector4(0, 0, 0, 1), Vector3.ONE, {
 		"display_name": display_name,
 		"catalog_id": cat_id
 	})
 	if new_id != "":
-		core.select_object(new_id)
 		_spawn_visual_node(new_id)
+		core.select_object(new_id)
+		_on_selection_changed(new_id)
 		_hierarchy_dock.refresh_tree()
 		_set_gizmo_mode(TransformGizmo3DClass.Mode.TRANSLATE)
 		_status_bar_label.text = "Spawned %s at (%.1f, 0, %.1f) | ✛ Move gizmo active" % [display_name, spawn_pos.x, spawn_pos.z]
@@ -425,13 +442,26 @@ func _setup_3d_viewport_scene(vp: SubViewport) -> void:
 	# Studio Baseplate Ground Mesh
 	_baseplate_mesh = MeshInstance3D.new()
 	var plane := PlaneMesh.new()
-	plane.size = Vector2(64, 64)
+	plane.size = Vector2(128, 128)
 	var gmat := StandardMaterial3D.new()
 	gmat.albedo_color = Color(0.20, 0.23, 0.27)
 	gmat.roughness = 0.85
 	_baseplate_mesh.mesh = plane
 	vp.add_child(_baseplate_mesh)
 
+	# Solid Physics Floor Collider (layer 1, 500x500m surface at Y=0)
+	var floor_body := StaticBody3D.new()
+	floor_body.name = "StudioFloorBody"
+	floor_body.set_collision_layer_value(1, true)
+	floor_body.set_collision_mask_value(1, true)
+	var floor_col := CollisionShape3D.new()
+	var floor_box := BoxShape3D.new()
+	floor_box.size = Vector3(500.0, 2.0, 500.0)
+	floor_col.shape = floor_box
+	floor_col.position = Vector3(0, -1.0, 0)
+	floor_body.add_child(floor_col)
+	vp.add_child(floor_body)
+
 	# 3D Grid floor lines
 	var grid := _create_3d_grid(32, 1.0)
 	vp.add_child(grid)
@@ -470,7 +500,7 @@ func _setup_viewport_hud_overlay(parent: Control) -> void:
 	hud_bar.position = Vector2(16, -42)
 
 	var hud_text := Label.new()
-	hud_text.text = "🎥 RMB+WASD: Fly  |  🖱️ LMB: Click to Select  |  ✛ [2] Move  |  ↻ [3] Rotate  |  [F] Focus  |  ▶ [F5] Play  |  ❓ [F1] Help"
+	hud_text.text = "🎥 RMB+WASD: Fly  |  🖱️ LMB: Click/Drag to Move  |  ✛ [2] Move  |  ↻ [3] Rotate  |  [F] Focus  |  ▶ [F5] Play  |  ❓ [F1] Help"
 	hud_text.add_theme_font_size_override("font_size", 11)
 	hud_text.add_theme_color_override("font_color", Color(0.9, 0.92, 0.96))
 	hud_bar.add_child(hud_text)
@@ -497,6 +527,8 @@ func _create_3d_grid(size: int, step: float) -> Node3D:
 	return mi
 
 
+# ── Keyboard Shortcuts & Nudge ────────────────────────────────────────
+
 func _setup_shortcuts() -> void:
 	set_process_unhandled_key_input(true)
 
@@ -524,6 +556,26 @@ func _unhandled_key_input(event: InputEvent) -> void:
 			_simulation_mgr.stop_simulation()
 		else:
 			_simulation_mgr.start_play(true)
+	elif k.keycode == KEY_DELETE or k.keycode == KEY_BACKSPACE:
+		var sel := _get_selected_id()
+		if sel != "":
+			_delete_selected_object(sel)
+	elif k.keycode == KEY_BRACKETLEFT and not k.is_command_or_control_pressed():
+		_nudge_selected_rotation(-45.0)
+	elif k.keycode == KEY_BRACKETRIGHT and not k.is_command_or_control_pressed():
+		_nudge_selected_rotation(45.0)
+	elif k.keycode == KEY_LEFT and not k.is_command_or_control_pressed():
+		_nudge_selected_position(Vector3(-1, 0, 0))
+	elif k.keycode == KEY_RIGHT and not k.is_command_or_control_pressed():
+		_nudge_selected_position(Vector3(1, 0, 0))
+	elif k.keycode == KEY_UP and not k.is_command_or_control_pressed():
+		_nudge_selected_position(Vector3(0, 0, -1))
+	elif k.keycode == KEY_DOWN and not k.is_command_or_control_pressed():
+		_nudge_selected_position(Vector3(0, 0, 1))
+	elif k.keycode == KEY_PAGEUP:
+		_nudge_selected_position(Vector3(0, 1, 0))
+	elif k.keycode == KEY_PAGEDOWN:
+		_nudge_selected_position(Vector3(0, -1, 0))
 	elif k.keycode == KEY_1 and not k.is_command_or_control_pressed():
 		_set_gizmo_mode(TransformGizmo3DClass.Mode.NONE)
 	elif k.keycode == KEY_2 and not k.is_command_or_control_pressed():
@@ -533,13 +585,66 @@ func _unhandled_key_input(event: InputEvent) -> void:
 	elif k.keycode == KEY_4 and not k.is_command_or_control_pressed():
 		_set_gizmo_mode(TransformGizmo3DClass.Mode.SCALE)
 	elif k.keycode == KEY_F and not k.is_command_or_control_pressed():
-		var sel_id = core.selection.get_selected_id() if core.selection.has_method("get_selected_id") else ""
+		var sel_id := _get_selected_id()
 		if sel_id != "":
-			var n = _world_container.get_node_or_null(sel_id)
+			var n := _world_container.get_node_or_null(sel_id)
 			if n is Node3D and _camera_3d != null:
 				_camera_3d.focus_on(n.global_position)
 
 
+func _nudge_selected_position(dir: Vector3) -> void:
+	var sel := _get_selected_id()
+	if sel == "":
+		return
+	var node := _world_container.get_node_or_null(sel) as Node3D
+	if node == null:
+		return
+	var step: float = _snap_spin.value if _snap_spin else 1.0
+	var new_pos := node.position + dir * step
+	new_pos.y = maxf(0.0, new_pos.y)
+	node.position = new_pos
+	if _gizmo_3d != null:
+		_gizmo_3d.position = node.position
+	var chunk_pos := _godot_to_chunk_pos(new_pos)
+	core.move_object(sel, chunk_pos)
+	if _inspector_dock != null:
+		_inspector_dock.set_transform_values(new_pos, node.rotation_degrees.y, node.scale)
+	_status_bar_label.text = "Nudged %s to (%.1f, %.1f, %.1f)" % [sel, new_pos.x, new_pos.y, new_pos.z]
+
+
+func _nudge_selected_rotation(delta_deg: float) -> void:
+	var sel := _get_selected_id()
+	if sel == "":
+		return
+	var node := _world_container.get_node_or_null(sel) as Node3D
+	if node == null:
+		return
+	var new_yaw := fmod(node.rotation_degrees.y + delta_deg, 360.0)
+	node.rotation_degrees.y = new_yaw
+	if _gizmo_3d != null:
+		_gizmo_3d.quaternion = node.quaternion
+	var q := node.quaternion
+	var chunk_q := _godot_to_chunk_quat(q)
+	core.rotate_object(sel, Vector4(chunk_q.x, chunk_q.y, chunk_q.z, chunk_q.w))
+	if _inspector_dock != null:
+		_inspector_dock.set_transform_values(node.position, new_yaw, node.scale)
+	_status_bar_label.text = "Rotated %s to %.0f°" % [sel, new_yaw]
+
+
+func _delete_selected_object(obj_id: String) -> void:
+	if obj_id == "":
+		obj_id = _get_selected_id()
+	if obj_id == "":
+		return
+	core.delete_object(obj_id)
+	var node := _world_container.get_node_or_null(obj_id)
+	if node != null:
+		node.queue_free()
+	core.select_object("")
+	_hierarchy_dock.refresh_tree()
+	_status_bar_label.text = "Deleted object '%s' | Undo with [Ctrl+Z]" % obj_id
+
+
 func _set_gizmo_mode(mode: TransformGizmo3DClass.Mode) -> void:
 	if _gizmo_3d != null:
 		_gizmo_3d.set_mode(mode)
@@ -565,21 +670,188 @@ func _return_to_main_menu() -> void:
 	get_tree().change_scene_to_file("res://scenes/main_menu.tscn")
 
 
-# ── Interactive 3D Viewport Input & Raycast Picking ─────────────────────
+# ── Interactive 3D Viewport Input & Picking ───────────────────────────
 
 func handle_viewport_input(event: InputEvent) -> void:
 	if event is InputEventMouseButton:
 		var mb := event as InputEventMouseButton
-		if mb.button_index == MOUSE_BUTTON_LEFT and mb.pressed:
-			var hit_obj := _raycast_find_object(mb.position)
-			if hit_obj != null:
-				core.select_object(hit_obj.name)
-				if mb.double_click and _camera_3d != null:
-					_camera_3d.focus_on(hit_obj.global_position)
-				_status_bar_label.text = "Selected: %s | ✛ Drag handles or [2-4] switch tools" % hit_obj.name
+		if mb.button_index == MOUSE_BUTTON_LEFT:
+			if mb.pressed:
+				_handle_left_press(mb)
 			else:
-				core.select_object("")
-				_status_bar_label.text = "Deselected | Click an object or [+ Add] to build"
+				_handle_left_release(mb)
+
+	elif event is InputEventMouseMotion and _is_dragging:
+		var mm := event as InputEventMouseMotion
+		_handle_drag_motion(mm)
+
+
+func _handle_left_press(mb: InputEventMouseButton) -> void:
+	if _camera_3d == null or _world_container == null:
+		return
+
+	var ray_from: Vector3 = _camera_3d.project_ray_origin(mb.position)
+	var ray_dir: Vector3 = _camera_3d.project_ray_normal(mb.position)
+	var sel_id: String = _get_selected_id()
+
+	# 1. First priority: Check if clicking on Gizmo handle
+	if _gizmo_3d != null and _gizmo_3d.visible and sel_id != "":
+		var picked_axis: TransformGizmo3DClass.Axis = _gizmo_3d.pick_axis(ray_from, ray_dir)
+		if picked_axis != TransformGizmo3DClass.Axis.NONE:
+			_start_drag(picked_axis, mb.position)
+			return
+
+	# 2. Second priority: Check if clicking on a 3D world object
+	var hit_obj := _raycast_find_object(mb.position)
+	if hit_obj != null:
+		if hit_obj.name == sel_id and _gizmo_3d != null and _gizmo_3d.current_mode != TransformGizmo3DClass.Mode.NONE:
+			# Directly drag already selected object
+			_start_drag(TransformGizmo3DClass.Axis.XY, mb.position)
+			return
+
+		# Select new object
+		core.select_object(hit_obj.name)
+		if mb.double_click and _camera_3d != null:
+			_camera_3d.focus_on(hit_obj.global_position)
+		_status_bar_label.text = "Selected: %s | ✛ Drag model or handles to move" % hit_obj.name
+		return
+
+	# 3. Third: Clicked empty space -> deselect
+	_is_dragging = false
+	core.select_object("")
+	_status_bar_label.text = "Deselected | Click an object or [+ Add] to build"
+
+
+func _start_drag(axis: TransformGizmo3DClass.Axis, mouse_pos: Vector2) -> void:
+	var sel_id := _get_selected_id()
+	if sel_id == "":
+		return
+	var node := _world_container.get_node_or_null(sel_id) as Node3D
+	if node == null:
+		return
+
+	_is_dragging = true
+	_drag_axis = axis
+	_drag_start_mouse = mouse_pos
+	_drag_start_ground = _raycast_ground_plane(mouse_pos)
+	_drag_start_node_pos = node.position
+	_drag_start_node_rot_deg = node.rotation_degrees
+	_drag_start_node_scale = node.scale
+	_drag_accum_y = 0.0
+	_drag_accum_rot = 0.0
+	_drag_accum_scale = 0.0
+
+
+func _handle_drag_motion(mm: InputEventMouseMotion) -> void:
+	var sel_id := _get_selected_id()
+	if sel_id == "":
+		_is_dragging = false
+		return
+	var node := _world_container.get_node_or_null(sel_id) as Node3D
+	if node == null:
+		_is_dragging = false
+		return
+
+	var snap_step: float = _snap_spin.value if _snap_spin else 1.0
+
+	match _gizmo_3d.current_mode if _gizmo_3d else TransformGizmo3DClass.Mode.TRANSLATE:
+		TransformGizmo3DClass.Mode.TRANSLATE:
+			if _drag_axis == TransformGizmo3DClass.Axis.Y:
+				var dy: float = -mm.relative.y * 0.05
+				_drag_accum_y += dy
+				var new_y := maxf(0.0, _drag_start_node_pos.y + _drag_accum_y)
+				if snap_step > 0.0:
+					new_y = snappedf(new_y, snap_step)
+				node.position.y = new_y
+			elif _drag_axis == TransformGizmo3DClass.Axis.X:
+				var curr_ground := _raycast_ground_plane(mm.position)
+				var dx := curr_ground.x - _drag_start_ground.x
+				if snap_step > 0.0:
+					dx = snappedf(dx, snap_step)
+				node.position.x = _drag_start_node_pos.x + dx
+			elif _drag_axis == TransformGizmo3DClass.Axis.Z:
+				var curr_ground := _raycast_ground_plane(mm.position)
+				var dz := curr_ground.z - _drag_start_ground.z
+				if snap_step > 0.0:
+					dz = snappedf(dz, snap_step)
+				node.position.z = _drag_start_node_pos.z + dz
+			else:
+				# Free ground plane movement (XZ)
+				var curr_ground := _raycast_ground_plane(mm.position)
+				var delta := curr_ground - _drag_start_ground
+				var new_x := _drag_start_node_pos.x + delta.x
+				var new_z := _drag_start_node_pos.z + delta.z
+				if snap_step > 0.0:
+					new_x = snappedf(new_x, snap_step)
+					new_z = snappedf(new_z, snap_step)
+				node.position.x = new_x
+				node.position.z = new_z
+
+			if _gizmo_3d != null:
+				_gizmo_3d.position = node.position
+			if _inspector_dock != null:
+				_inspector_dock.set_transform_values(node.position, node.rotation_degrees.y, node.scale)
+			_status_bar_label.text = "Moving %s to (%.1f, %.1f, %.1f)" % [sel_id, node.position.x, node.position.y, node.position.z]
+
+		TransformGizmo3DClass.Mode.ROTATE:
+			var rot_step: float = 15.0
+			_drag_accum_rot += mm.relative.x * 0.8
+			var new_yaw := _drag_start_node_rot_deg.y - _drag_accum_rot
+			if rot_step > 0.0:
+				new_yaw = snappedf(new_yaw, rot_step)
+			node.rotation_degrees.y = new_yaw
+			if _gizmo_3d != null:
+				_gizmo_3d.quaternion = node.quaternion
+			if _inspector_dock != null:
+				_inspector_dock.set_transform_values(node.position, new_yaw, node.scale)
+			_status_bar_label.text = "Rotating %s to %.0f°" % [sel_id, new_yaw]
+
+		TransformGizmo3DClass.Mode.SCALE:
+			var scale_step: float = 0.1
+			_drag_accum_scale += -mm.relative.y * 0.02
+			var factor := maxf(0.05, 1.0 + _drag_accum_scale)
+			var new_scale := _drag_start_node_scale * factor
+			if scale_step > 0.0:
+				new_scale.x = snappedf(new_scale.x, scale_step)
+				new_scale.y = snappedf(new_scale.y, scale_step)
+				new_scale.z = snappedf(new_scale.z, scale_step)
+			node.scale = new_scale
+			if _gizmo_3d != null:
+				_gizmo_3d.attach_to_node(node)
+			if _inspector_dock != null:
+				_inspector_dock.set_transform_values(node.position, node.rotation_degrees.y, new_scale)
+			_status_bar_label.text = "Scaling %s to (%.2f, %.2f, %.2f)" % [sel_id, new_scale.x, new_scale.y, new_scale.z]
+
+
+func _handle_left_release(_mb: InputEventMouseButton) -> void:
+	if not _is_dragging:
+		return
+	_is_dragging = false
+	var sel_id := _get_selected_id()
+	if sel_id == "":
+		return
+	var node := _world_container.get_node_or_null(sel_id) as Node3D
+	if node == null:
+		return
+
+	match _gizmo_3d.current_mode if _gizmo_3d else TransformGizmo3DClass.Mode.TRANSLATE:
+		TransformGizmo3DClass.Mode.TRANSLATE:
+			var chunk_pos := _godot_to_chunk_pos(node.position)
+			core.move_object(sel_id, chunk_pos)
+			_status_bar_label.text = "Moved %s to (%.1f, %.1f, %.1f) | Undo with [Ctrl+Z]" % [sel_id, node.position.x, node.position.y, node.position.z]
+
+		TransformGizmo3DClass.Mode.ROTATE:
+			var q := node.quaternion
+			var chunk_q := _godot_to_chunk_quat(q)
+			core.rotate_object(sel_id, Vector4(chunk_q.x, chunk_q.y, chunk_q.z, chunk_q.w))
+			_status_bar_label.text = "Rotated %s to %.0f° | Undo with [Ctrl+Z]" % [sel_id, node.rotation_degrees.y]
+
+		TransformGizmo3DClass.Mode.SCALE:
+			var chunk_scale := _godot_to_chunk_scale(node.scale)
+			core.scale_object(sel_id, chunk_scale)
+			_status_bar_label.text = "Scaled %s to (%.2f, %.2f, %.2f) | Undo with [Ctrl+Z]" % [sel_id, node.scale.x, node.scale.y, node.scale.z]
+
+	_hierarchy_dock.refresh_tree()
 
 
 func handle_viewport_drop(at_pos: Vector2, data: Variant) -> void:
@@ -591,21 +863,24 @@ func handle_viewport_drop(at_pos: Vector2, data: Variant) -> void:
 	var new_id: String = ""
 
 	if target_obj != null and target_obj.name != "":
-		new_id = core.place_object_stacked(cat_id, target_obj.name, drop_pos, Vector3(0, 0, 1), 0.0, false, {
+		var target_chunk_pos := _godot_to_chunk_pos(drop_pos)
+		new_id = core.place_object_stacked(cat_id, target_obj.name, target_chunk_pos, Vector3(0, 0, 1), 0.0, false, {
 			"display_name": data.get("name", cat_id),
 			"catalog_id": cat_id,
 			"asset_id": data.get("asset_id", "")
 		})
 	else:
-		new_id = core.place_object(cat_id, drop_pos, Vector4(0, 0, 0, 1), Vector3.ONE, {
+		var chunk_pos := _godot_to_chunk_pos(drop_pos)
+		new_id = core.place_object(cat_id, chunk_pos, Vector4(0, 0, 0, 1), Vector3.ONE, {
 			"display_name": data.get("name", cat_id),
 			"catalog_id": cat_id,
 			"asset_id": data.get("asset_id", "")
 		})
 
 	if new_id != "":
-		core.select_object(new_id)
 		_spawn_visual_node(new_id)
+		core.select_object(new_id)
+		_on_selection_changed(new_id)
 		_hierarchy_dock.refresh_tree()
 		_set_gizmo_mode(TransformGizmo3DClass.Mode.TRANSLATE)
 		_status_bar_label.text = "Placed %s at (%.1f, %.1f, %.1f)" % [data.get("name", cat_id), drop_pos.x, drop_pos.y, drop_pos.z]
@@ -661,17 +936,63 @@ func _raycast_ground_plane(screen_pos: Vector2) -> Vector3:
 	return from + dir * t
 
 
+# ── Coordinate Conversions ────────────────────────────────────────────
+
+static func _godot_to_chunk_pos(g: Vector3) -> Vector3:
+	return Vector3(g.x, g.z, g.y)
+
+static func _chunk_to_godot_pos(c: Vector3) -> Vector3:
+	return Vector3(c.x, c.z, c.y)
+
+static func _godot_to_chunk_quat(q: Quaternion) -> Quaternion:
+	return Quaternion(q.x, q.z, q.y, q.w)
+
+static func _chunk_to_godot_quat(q: Quaternion) -> Quaternion:
+	return Quaternion(q.x, q.z, q.y, q.w)
+
+static func _godot_to_chunk_scale(s: Vector3) -> Vector3:
+	return Vector3(s.x, s.z, s.y)
+
+static func _chunk_to_godot_scale(s: Vector3) -> Vector3:
+	return Vector3(s.x, s.z, s.y)
+
+
 # ── Selection & Scene Visual Sync ─────────────────────────────────────
 
+func _get_selected_id() -> String:
+	if core != null and core.selection != null:
+		return core.selection.get_selected()
+	return ""
+
+
 func _on_selection_changed(obj_id: String) -> void:
 	if obj_id == "":
-		_gizmo_3d.attach_to_node(null)
+		if _gizmo_3d != null:
+			_gizmo_3d.attach_to_node(null)
 		return
 
-	var obj_node = _world_container.get_node_or_null(obj_id)
-	if obj_node is Node3D:
+	var obj_node := _world_container.get_node_or_null(obj_id)
+	if obj_node is Node3D and _gizmo_3d != null:
+		if _gizmo_3d.current_mode == TransformGizmo3DClass.Mode.NONE:
+			_set_gizmo_mode(TransformGizmo3DClass.Mode.TRANSLATE)
 		_gizmo_3d.attach_to_node(obj_node)
-		_camera_3d.focus_on(obj_node.global_position)
+
+
+func _on_inspector_property_changed(obj_id: String, prop_name: String, val: Variant) -> void:
+	var node := _world_container.get_node_or_null(obj_id) as Node3D
+	if node == null:
+		return
+	match prop_name:
+		"position":
+			node.position = val as Vector3
+			if _gizmo_3d != null:
+				_gizmo_3d.position = node.position
+		"rotation":
+			node.quaternion = val as Quaternion
+			if _gizmo_3d != null:
+				_gizmo_3d.quaternion = node.quaternion
+		"scale":
+			node.scale = val as Vector3
 
 
 func _on_collection_model_selected(model_data: Dictionary) -> void:
@@ -680,14 +1001,16 @@ func _on_collection_model_selected(model_data: Dictionary) -> void:
 	if _camera_3d != null:
 		spawn_pos = _camera_3d.focal_point
 		spawn_pos.y = 0.0
-	var new_id := core.place_object(cat_id, spawn_pos, Vector4(0, 0, 0, 1), Vector3.ONE, {
+	var chunk_pos := _godot_to_chunk_pos(spawn_pos)
+	var new_id := core.place_object(cat_id, chunk_pos, Vector4(0, 0, 0, 1), Vector3.ONE, {
 		"display_name": model_data.get("name", cat_id),
 		"catalog_id": cat_id,
 		"asset_id": model_data.get("asset_id", "")
 	})
 	if new_id != "":
-		core.select_object(new_id)
 		_spawn_visual_node(new_id)
+		core.select_object(new_id)
+		_on_selection_changed(new_id)
 		_hierarchy_dock.refresh_tree()
 		_set_gizmo_mode(TransformGizmo3DClass.Mode.TRANSLATE)
 		_status_bar_label.text = "Placed %s at (%.1f, 0, %.1f)" % [model_data.get("name", cat_id), spawn_pos.x, spawn_pos.z]
@@ -707,7 +1030,9 @@ func _spawn_visual_node(obj_id: String) -> void:
 	var node = StaticObjectNodeClass.new()
 	node.name = obj.id
 	node.world_object = wo
-	node.position = Vector3(obj.position.x, obj.position.z, obj.position.y)
+	node.position = _chunk_to_godot_pos(obj.position)
+	node.quaternion = _chunk_to_godot_quat(Quaternion(obj.rotation.x, obj.rotation.y, obj.rotation.z, obj.rotation.w))
+	node.scale = _chunk_to_godot_scale(obj.scale)
 	_world_container.add_child(node)
 
 
@@ -736,9 +1061,10 @@ func load_template(template_name: String) -> void:
 			obj.get("properties", {})
 		)
 	_refresh_scene_visuals()
-	# Select mascot or first object to showcase inspector & gizmo
 	if not core.model.payload.objects.is_empty():
-		core.select_object(core.model.payload.objects[0].id)
+		var first_id: String = core.model.payload.objects[0].id
+		core.select_object(first_id)
+		_on_selection_changed(first_id)
 		_set_gizmo_mode(TransformGizmo3DClass.Mode.TRANSLATE)
 	_status_bar_label.text = "Loaded template: %s | Press [F1] for Controls" % project_title
 
@@ -770,6 +1096,10 @@ func _update_simulation_ui(playing: bool) -> void:
 	_btn_play.disabled = playing
 	_btn_stop.disabled = not playing
 	_status_bar_label.text = "Simulation: PLAYING (F5 to Stop)" if playing else "Simulation: STOPPED (Edit mode)"
+	if not playing:
+		if _camera_3d != null:
+			_camera_3d.current = true
+		Input.mouse_mode = Input.MOUSE_MODE_VISIBLE
 
 
 # ── Menu Bar Dispatch ────────────────────────────────────────────────
@@ -789,7 +1119,7 @@ func _on_edit_menu_pressed(id: int) -> void:
 		0: core.undo(); _refresh_scene_visuals()
 		1: core.redo(); _refresh_scene_visuals()
 		2: _hierarchy_dock._on_duplicate_pressed()
-		3: _hierarchy_dock._on_delete_pressed()
+		3: _delete_selected_object(_get_selected_id())
 
 
 func _on_view_menu_pressed(id: int) -> void:
@@ -799,9 +1129,9 @@ func _on_view_menu_pressed(id: int) -> void:
 		2: _camera_3d.set_view_preset(StudioViewportCameraClass.ViewPreset.FRONT)
 		3: _camera_3d.set_view_preset(StudioViewportCameraClass.ViewPreset.SIDE)
 		4:
-			var sel_id = core.selection.get_selected_id() if core.selection.has_method("get_selected_id") else ""
+			var sel_id := _get_selected_id()
 			if sel_id != "":
-				var n = _world_container.get_node_or_null(sel_id)
+				var n := _world_container.get_node_or_null(sel_id)
 				if n is Node3D and _camera_3d != null:
 					_camera_3d.focus_on(n.global_position)