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

scripts/smoke_test_studio_interaction.gd

@@ -0,0 +1,158 @@
+extends SceneTree
+## Headless smoke test verifying Studio floor collision, selection,
+## gizmo ray picking, inspector property sync, and transformation manipulation.
+
+var _failures: int = 0
+var _checks: int = 0
+
+const StudioMainClass = preload("res://scripts/studio/studio_main.gd")
+const TransformGizmo3DClass = preload("res://scripts/studio/gizmos/transform_gizmo_3d.gd")
+
+func _init() -> void:
+	print("--- Running Smoke Test: Studio Viewport Interaction & Floor Collision ---")
+	test_floor_collision_body()
+	test_inspector_sync_and_visual_transform()
+	test_gizmo_picking_and_dragging()
+	test_nudge_shortcuts_and_delete()
+
+	if _failures == 0:
+		print("--- PASS: All %d studio interaction checks passed! ---" % _checks)
+		quit(0)
+	else:
+		printerr("--- FAIL: %d failures out of %d checks ---" % [_failures, _checks])
+		quit(1)
+
+
+func _check(desc: String, cond: bool) -> void:
+	_checks += 1
+	if cond:
+		print("  ✓ %s" % desc)
+	else:
+		_failures += 1
+		printerr("  ✗ FAIL: %s" % desc)
+
+
+func test_floor_collision_body() -> void:
+	print("Testing Studio floor collision setup...")
+	var studio := StudioMainClass.new()
+	root.add_child(studio)
+
+	var floor_body = studio._sub_viewport.find_child("StudioFloorBody", true, false)
+	_check("StudioFloorBody exists in 3D viewport", floor_body != null)
+	if floor_body is StaticBody3D:
+		var sb := floor_body as StaticBody3D
+		_check("Floor body has collision layer 1 enabled", sb.get_collision_layer_value(1))
+		_check("Floor body has collision mask 1 enabled", sb.get_collision_mask_value(1))
+		var col = sb.find_child("*", true, false) as CollisionShape3D
+		_check("Floor body has CollisionShape3D", col != null and col.shape is BoxShape3D)
+		if col != null and col.shape is BoxShape3D:
+			var box := col.shape as BoxShape3D
+			_check("Floor collider spans at least 100x100m", box.size.x >= 100.0 and box.size.z >= 100.0)
+
+	studio.queue_free()
+
+
+func test_inspector_sync_and_visual_transform() -> void:
+	print("Testing Inspector property sync to 3D visual nodes...")
+	var studio := StudioMainClass.new()
+	root.add_child(studio)
+
+	# Place an object
+	var obj_id := studio.core.place_object("crate_small", Vector3(10, 20, 0))
+	studio._spawn_visual_node(obj_id)
+	studio._on_selection_changed(obj_id)
+
+	var visual_node := studio._world_container.get_node_or_null(obj_id) as Node3D
+	_check("Visual node exists in world container", visual_node != null)
+
+	# Simulate inspector position change (moving object via Inspector)
+	studio._inspector_dock._pos_x.value = 15.0
+	studio._inspector_dock._pos_y.value = 3.0
+	studio._inspector_dock._pos_z.value = 25.0
+	studio._inspector_dock._on_pos_changed(0.0)
+
+	_check("Visual node position updated to match Inspector X", is_equal_approx(visual_node.position.x, 15.0))
+	_check("Visual node position updated to match Inspector Y (height)", is_equal_approx(visual_node.position.y, 3.0))
+	_check("Visual node position updated to match Inspector Z (depth)", is_equal_approx(visual_node.position.z, 25.0))
+
+	# Simulate inspector yaw rotation change
+	studio._inspector_dock._rot_y.value = 90.0
+	studio._inspector_dock._on_rot_changed(90.0)
+	_check("Visual node rotated to match Inspector Yaw", absf(visual_node.rotation_degrees.y - 90.0) < 0.1)
+
+	# Simulate inspector scale change
+	studio._inspector_dock._scale_x.value = 2.0
+	studio._inspector_dock._scale_y.value = 1.5
+	studio._inspector_dock._scale_z.value = 2.0
+	studio._inspector_dock._on_scale_changed(0.0)
+	_check("Visual node scale updated to match Inspector", is_equal_approx(visual_node.scale.x, 2.0) and is_equal_approx(visual_node.scale.y, 1.5))
+
+	studio.queue_free()
+
+
+func test_gizmo_picking_and_dragging() -> void:
+	print("Testing Gizmo geometric picking and axis detection...")
+	var studio := StudioMainClass.new()
+	root.add_child(studio)
+
+	var obj_id := studio.core.place_object("bison", Vector3(0, 0, 0))
+	studio._spawn_visual_node(obj_id)
+	studio._on_selection_changed(obj_id)
+
+	var gizmo = studio._gizmo_3d
+	_check("Gizmo is attached and visible on selection", gizmo != null and gizmo.visible)
+
+	# Test X axis picking (ray aimed near +X arrow at (1.0, 0, 0) relative to gizmo)
+	var ray_origin: Vector3 = gizmo.position + Vector3(1.0, 5.0, 0.0)
+	var ray_dir: Vector3 = Vector3(0.0, -1.0, 0.0)
+	var picked_axis = gizmo.pick_axis(ray_origin, ray_dir)
+	_check("Gizmo ray picking correctly identified X axis", picked_axis == TransformGizmo3DClass.Axis.X)
+
+	# Test Y axis picking (ray aimed near +Y arrow at (0, 1.0, 0) relative to gizmo)
+	ray_origin = gizmo.position + Vector3(0.0, 1.0, 5.0)
+	ray_dir = Vector3(0.0, 0.0, -1.0)
+	picked_axis = gizmo.pick_axis(ray_origin, ray_dir)
+	_check("Gizmo ray picking correctly identified Y axis", picked_axis == TransformGizmo3DClass.Axis.Y)
+
+	# Test Z axis picking (ray aimed near +Z arrow at (0, 0, 1.0) relative to gizmo)
+	ray_origin = gizmo.position + Vector3(0.0, 5.0, 1.0)
+	ray_dir = Vector3(0.0, -1.0, 0.0)
+	picked_axis = gizmo.pick_axis(ray_origin, ray_dir)
+	_check("Gizmo ray picking correctly identified Z axis", picked_axis == TransformGizmo3DClass.Axis.Z)
+
+	# Test Center picking (ray aimed at gizmo origin)
+	ray_origin = gizmo.position + Vector3(0.0, 5.0, 0.0)
+	ray_dir = Vector3(0.0, -1.0, 0.0)
+	picked_axis = gizmo.pick_axis(ray_origin, ray_dir)
+	_check("Gizmo ray picking correctly identified Center/Plane handle", picked_axis == TransformGizmo3DClass.Axis.XY)
+
+	studio.queue_free()
+
+
+func test_nudge_shortcuts_and_delete() -> void:
+	print("Testing keyboard nudge shortcuts and object deletion...")
+	var studio := StudioMainClass.new()
+	root.add_child(studio)
+
+	var obj_id := studio.core.place_object("crate_small", Vector3(0, 0, 0))
+	studio._spawn_visual_node(obj_id)
+	studio.core.select_object(obj_id)
+	studio._on_selection_changed(obj_id)
+
+	var visual_node := studio._world_container.get_node_or_null(obj_id) as Node3D
+
+	# Nudge position right (+X)
+	var old_x = visual_node.position.x
+	studio._nudge_selected_position(Vector3(1, 0, 0))
+	_check("Nudge right moved visual node +X by 1.0", is_equal_approx(visual_node.position.x, old_x + 1.0))
+
+	# Nudge rotation
+	studio._nudge_selected_rotation(45.0)
+	_check("Nudge rotation rotated visual node by 45 degrees", is_equal_approx(visual_node.rotation_degrees.y, 45.0))
+
+	# Delete object
+	studio._delete_selected_object(obj_id)
+	_check("Object deleted from Core model", studio.core.model.find_object(obj_id) == null)
+	_check("Selection cleared after delete", studio.core.selection.get_selected() == "")
+
+	studio.queue_free()

scripts/studio/gizmos/transform_gizmo_3d.gd

@@ -1,6 +1,8 @@
 class_name TransformGizmo3D
 extends Node3D
 ## Interactive 3D manipulator gizmo supporting Translate, Rotate, and Scale modes with snapping.
+## Renders visually clear axis handles (arrows for move, rings for rotate, cubes for scale)
+## with priority depth rendering and geometric raycast picking.
 
 signal transform_started
 signal transform_updated(mode: String, delta: Variant)
@@ -24,17 +26,26 @@ var _drag_start_pos: Vector3 = Vector3.ZERO
 var _drag_start_rot: Vector3 = Vector3.ZERO
 var _drag_start_scale: Vector3 = Vector3.ONE
 
+# Mode visual root nodes
+var _translate_root: Node3D
+var _rotate_root: Node3D
+var _scale_root: Node3D
+
 
 func _ready() -> void:
 	_build_gizmo_visuals()
+	_update_visual_mode()
 
 
 func attach_to_node(node: Node3D) -> void:
 	target_node = node
-	if target_node != null:
+	if target_node != null and is_instance_valid(target_node):
-		visible = true
+		visible = (current_mode != Mode.NONE)
-		global_position = target_node.global_position
+		position = target_node.position
-		global_rotation = target_node.global_rotation
+		if current_mode == Mode.ROTATE or current_mode == Mode.SCALE:
+			quaternion = target_node.quaternion
+		else:
+			quaternion = Quaternion.IDENTITY
 	else:
 		visible = false
 
@@ -42,6 +53,8 @@ func attach_to_node(node: Node3D) -> void:
 func set_mode(new_mode: Mode) -> void:
 	current_mode = new_mode
 	_update_visual_mode()
+	if target_node != null and is_instance_valid(target_node):
+		attach_to_node(target_node)
 
 
 func set_snap(enabled: bool, translate_step: float = 1.0, rotate_step: float = 15.0) -> void:
@@ -50,63 +63,269 @@ func set_snap(enabled: bool, translate_step: float = 1.0, rotate_step: float = 1
 	snap_rotate_deg = rotate_step
 
 
+func _update_visual_mode() -> void:
+	if _translate_root != null:
+		_translate_root.visible = (current_mode == Mode.TRANSLATE)
+	if _rotate_root != null:
+		_rotate_root.visible = (current_mode == Mode.ROTATE)
+	if _scale_root != null:
+		_scale_root.visible = (current_mode == Mode.SCALE)
+	visible = (target_node != null and current_mode != Mode.NONE)
+
+
+# ── Visual Construction ───────────────────────────────────────────────
+
+func _make_gizmo_mat(color: Color) -> StandardMaterial3D:
+	var mat := StandardMaterial3D.new()
+	mat.albedo_color = color
+	mat.shading_mode = BaseMaterial3D.SHADING_MODE_UNSHADED
+	mat.no_depth_test = true
+	mat.render_priority = 10
+	return mat
+
+
 func _build_gizmo_visuals() -> void:
-	# Build colored 3D axis handles for X (Red), Y (Green), Z (Blue)
+	var x_mat := _make_gizmo_mat(Color(0.95, 0.22, 0.22))
-	var x_mat := StandardMaterial3D.new()
+	var y_mat := _make_gizmo_mat(Color(0.22, 0.90, 0.25))
-	x_mat.albedo_color = Color(0.9, 0.2, 0.2)
+	var z_mat := _make_gizmo_mat(Color(0.25, 0.50, 0.98))
-	x_mat.shading_mode = BaseMaterial3D.SHADING_MODE_UNSHADED
+	var center_mat := _make_gizmo_mat(Color(1.0, 0.88, 0.20))
 
-	var y_mat := StandardMaterial3D.new()
+	# 1. TRANSLATE Visuals (Arrows + Center Ground Plane Quad)
-	y_mat.albedo_color = Color(0.2, 0.85, 0.2)
+	_translate_root = Node3D.new()
-	y_mat.shading_mode = BaseMaterial3D.SHADING_MODE_UNSHADED
+	_translate_root.name = "TranslateRoot"
+	add_child(_translate_root)
 
-	var z_mat := StandardMaterial3D.new()
+	_translate_root.add_child(_create_arrow(Vector3(1, 0, 0), x_mat, "ArrowX"))
-	z_mat.albedo_color = Color(0.2, 0.4, 0.95)
+	_translate_root.add_child(_create_arrow(Vector3(0, 1, 0), y_mat, "ArrowY"))
-	z_mat.shading_mode = BaseMaterial3D.SHADING_MODE_UNSHADED
+	_translate_root.add_child(_create_arrow(Vector3(0, 0, 1), z_mat, "ArrowZ"))
 
-	# X axis line + arrow
+	# Center ground plane indicator
-	var x_axis := _create_axis_cylinder(Vector3(1, 0, 0), x_mat)
+	var plane_inst := MeshInstance3D.new()
-	x_axis.name = "AxisX"
+	var plane_mesh := BoxMesh.new()
-	add_child(x_axis)
+	plane_mesh.size = Vector3(0.4, 0.02, 0.4)
+	plane_inst.mesh = plane_mesh
+	plane_inst.material_override = center_mat
+	plane_inst.position = Vector3(0.2, 0.01, 0.2)
+	_translate_root.add_child(plane_inst)
 
-	# Y axis line + arrow
+	# 2. ROTATE Visuals (Rings)
-	var y_axis := _create_axis_cylinder(Vector3(0, 1, 0), y_mat)
+	_rotate_root = Node3D.new()
-	y_axis.name = "AxisY"
+	_rotate_root.name = "RotateRoot"
-	add_child(y_axis)
+	add_child(_rotate_root)
 
-	# Z axis line + arrow
+	_rotate_root.add_child(_create_torus(Vector3.UP, y_mat, "RingYaw"))
-	var z_axis := _create_axis_cylinder(Vector3(0, 0, 1), z_mat)
+	_rotate_root.add_child(_create_torus(Vector3.RIGHT, x_mat, "RingPitch"))
-	z_axis.name = "AxisZ"
+	_rotate_root.add_child(_create_torus(Vector3.FORWARD, z_mat, "RingRoll"))
-	add_child(z_axis)
+
+	# 3. SCALE Visuals (Lines + End Cubes)
+	_scale_root = Node3D.new()
+	_scale_root.name = "ScaleRoot"
+	add_child(_scale_root)
+
+	_scale_root.add_child(_create_scale_handle(Vector3(1, 0, 0), x_mat, "ScaleX"))
+	_scale_root.add_child(_create_scale_handle(Vector3(0, 1, 0), y_mat, "ScaleY"))
+	_scale_root.add_child(_create_scale_handle(Vector3(0, 0, 1), z_mat, "ScaleZ"))
+
+	# Center uniform scale cube
+	var center_cube := MeshInstance3D.new()
+	var c_box := BoxMesh.new()
+	c_box.size = Vector3(0.25, 0.25, 0.25)
+	center_cube.mesh = c_box
+	center_cube.material_override = center_mat
+	_scale_root.add_child(center_cube)
 
 
-func _create_axis_cylinder(dir: Vector3, mat: Material) -> Node3D:
+func _create_arrow(dir: Vector3, mat: Material, node_name: String) -> Node3D:
 	var container := Node3D.new()
+	container.name = node_name
+
+	# Shaft
 	var shaft := MeshInstance3D.new()
 	var cyl := CylinderMesh.new()
-	cyl.top_radius = 0.03
+	cyl.top_radius = 0.035
-	cyl.bottom_radius = 0.03
+	cyl.bottom_radius = 0.035
-	cyl.height = 1.5
+	cyl.height = 1.3
-	cyl.material = mat
 	shaft.mesh = cyl
+	shaft.material_override = mat
+
+	# Cone Head
+	var head := MeshInstance3D.new()
+	var cone := CylinderMesh.new()
+	cone.top_radius = 0.0
+	cone.bottom_radius = 0.12
+	cone.height = 0.35
+	head.mesh = cone
+	head.material_override = mat
 
-	# Point cylinder along direction
 	if dir == Vector3(1, 0, 0):
 		shaft.rotation_degrees = Vector3(0, 0, -90)
-		shaft.position = Vector3(0.75, 0, 0)
+		shaft.position = Vector3(0.65, 0, 0)
+		head.rotation_degrees = Vector3(0, 0, -90)
+		head.position = Vector3(1.45, 0, 0)
 	elif dir == Vector3(0, 1, 0):
-		shaft.position = Vector3(0, 0.75, 0)
+		shaft.position = Vector3(0, 0.65, 0)
+		head.position = Vector3(0, 1.45, 0)
 	elif dir == Vector3(0, 0, 1):
 		shaft.rotation_degrees = Vector3(90, 0, 0)
-		shaft.position = Vector3(0, 0, 0.75)
+		shaft.position = Vector3(0, 0, 0.65)
+		head.rotation_degrees = Vector3(90, 0, 0)
+		head.position = Vector3(0, 0, 1.45)
 
 	container.add_child(shaft)
+	container.add_child(head)
 	return container
 
 
-func _update_visual_mode() -> void:
+func _create_torus(normal: Vector3, mat: Material, node_name: String) -> Node3D:
-	visible = (target_node != null and current_mode != Mode.NONE)
+	var inst := MeshInstance3D.new()
+	inst.name = node_name
+	var torus := TorusMesh.new()
+	torus.inner_radius = 1.25
+	torus.outer_radius = 1.35
+	torus.rings = 32
+	torus.ring_segments = 8
+	inst.mesh = torus
+	inst.material_override = mat
 
+	if normal == Vector3.RIGHT:
+		inst.rotation_degrees = Vector3(0, 0, 90)
+	elif normal == Vector3.FORWARD:
+		inst.rotation_degrees = Vector3(90, 0, 0)
+
+	return inst
+
+
+func _create_scale_handle(dir: Vector3, mat: Material, node_name: String) -> Node3D:
+	var container := Node3D.new()
+	container.name = node_name
+
+	# Shaft
+	var shaft := MeshInstance3D.new()
+	var cyl := CylinderMesh.new()
+	cyl.top_radius = 0.035
+	cyl.bottom_radius = 0.035
+	cyl.height = 1.3
+	shaft.mesh = cyl
+	shaft.material_override = mat
+
+	# Cube Tip
+	var tip := MeshInstance3D.new()
+	var box := BoxMesh.new()
+	box.size = Vector3(0.2, 0.2, 0.2)
+	tip.mesh = box
+	tip.material_override = mat
+
+	if dir == Vector3(1, 0, 0):
+		shaft.rotation_degrees = Vector3(0, 0, -90)
+		shaft.position = Vector3(0.65, 0, 0)
+		tip.position = Vector3(1.35, 0, 0)
+	elif dir == Vector3(0, 1, 0):
+		shaft.position = Vector3(0, 0.65, 0)
+		tip.position = Vector3(0, 1.35, 0)
+	elif dir == Vector3(0, 0, 1):
+		shaft.rotation_degrees = Vector3(90, 0, 0)
+		shaft.position = Vector3(0, 0, 0.65)
+		tip.position = Vector3(0, 0, 1.35)
+
+	container.add_child(shaft)
+	container.add_child(tip)
+	return container
+
+
+# ── Geometric Axis Picking ────────────────────────────────────────────
+
+func pick_axis(ray_origin: Vector3, ray_dir: Vector3) -> Axis:
+	if not visible or target_node == null:
+		return Axis.NONE
+
+	var origin := position
+	# 1. Center / Ground plane handle test (radius 0.45)
+	var d_center := _point_to_ray_dist(origin, ray_origin, ray_dir)
+	if d_center < 0.45:
+		return Axis.XY
+
+	match current_mode:
+		Mode.TRANSLATE:
+			var d_x := get_ray_segment_distance(ray_origin, ray_dir, origin, origin + Vector3(1.6, 0, 0))
+			var d_y := get_ray_segment_distance(ray_origin, ray_dir, origin, origin + Vector3(0, 1.6, 0))
+			var d_z := get_ray_segment_distance(ray_origin, ray_dir, origin, origin + Vector3(0, 0, 1.6))
+			var min_d := minf(d_x, minf(d_y, d_z))
+			if min_d < 0.35:
+				if min_d == d_y: return Axis.Y
+				if min_d == d_x: return Axis.X
+				if min_d == d_z: return Axis.Z
+
+		Mode.ROTATE:
+			var d_yaw := _ray_ring_distance(ray_origin, ray_dir, origin, Vector3.UP, 1.3)
+			var d_pitch := _ray_ring_distance(ray_origin, ray_dir, origin, Vector3.RIGHT, 1.3)
+			var d_roll := _ray_ring_distance(ray_origin, ray_dir, origin, Vector3.FORWARD, 1.3)
+			var min_r := minf(d_yaw, minf(d_pitch, d_roll))
+			if min_r < 0.40:
+				if min_r == d_yaw: return Axis.Y
+				if min_r == d_pitch: return Axis.X
+				if min_r == d_roll: return Axis.Z
+
+		Mode.SCALE:
+			var d_x := get_ray_segment_distance(ray_origin, ray_dir, origin, origin + Vector3(1.5, 0, 0))
+			var d_y := get_ray_segment_distance(ray_origin, ray_dir, origin, origin + Vector3(0, 1.5, 0))
+			var d_z := get_ray_segment_distance(ray_origin, ray_dir, origin, origin + Vector3(0, 0, 1.5))
+			var min_d := minf(d_x, minf(d_y, d_z))
+			if min_d < 0.35:
+				if min_d == d_y: return Axis.Y
+				if min_d == d_x: return Axis.X
+				if min_d == d_z: return Axis.Z
+
+	return Axis.NONE
+
+
+static func _point_to_ray_dist(p: Vector3, ray_origin: Vector3, ray_dir: Vector3) -> float:
+	var u := ray_dir.normalized()
+	var to_p := p - ray_origin
+	var proj := to_p.dot(u)
+	if proj < 0.0:
+		return 1e9
+	var closest := ray_origin + u * proj
+	return p.distance_to(closest)
+
+
+static func _ray_ring_distance(ray_origin: Vector3, ray_dir: Vector3, ring_center: Vector3, ring_normal: Vector3, ring_radius: float) -> float:
+	var denom := ray_dir.dot(ring_normal)
+	if absf(denom) < 1e-5:
+		return 1e9
+	var t := (ring_center - ray_origin).dot(ring_normal) / denom
+	if t < 0.0:
+		return 1e9
+	var hit := ray_origin + ray_dir * t
+	var d_from_center := hit.distance_to(ring_center)
+	return absf(d_from_center - ring_radius)
+
+
+static func get_ray_segment_distance(ray_origin: Vector3, ray_dir: Vector3, seg_a: Vector3, seg_b: Vector3) -> float:
+	var u := ray_dir.normalized()
+	var v := seg_b - seg_a
+	var w0 := ray_origin - seg_a
+	var a := u.dot(u)
+	var b := u.dot(v)
+	var c := v.dot(v)
+	var d := u.dot(w0)
+	var e := v.dot(w0)
+	var denom := a * c - b * b
+	var s: float = 0.0
+	var t: float = 0.0
+	if denom > 1e-6:
+		s = (b * e - c * d) / denom
+		t = (a * e - b * d) / denom
+	else:
+		s = 0.0
+		t = e / c if c > 1e-6 else 0.0
+	s = maxf(0.0, s)
+	t = clampf(t, 0.0, 1.0)
+	var pt_ray := ray_origin + u * s
+	var pt_seg := seg_a + v * t
+	return pt_ray.distance_to(pt_seg)
+
+
+# ── Drag Lifecycle (Backwards Compatibility) ──────────────────────────
 
 func start_drag(axis: Axis) -> void:
 	if target_node == null:

scripts/studio/studio_inspector_dock.gd

@@ -2,6 +2,7 @@ class_name StudioInspectorDock
 extends VBoxContainer
 ## Property Inspector Dock for ModBison Studio.
 ## Renders editable properties for selected world object(s) with undo/redo support.
+## Synchronizes Godot 3D world transforms (X, Y_height, Z_depth) with Chunk storage.
 
 signal property_changed(object_id: String, key: String, value: Variant)
 signal delete_requested(object_id: String)
@@ -15,7 +16,7 @@ var _empty_label: Label
 var _scroll: ScrollContainer
 var _content_vbox: VBoxContainer
 
-# Transform fields
+# Transform fields (Godot 3D: X, Y_up, Z_depth)
 var _pos_x: SpinBox
 var _pos_y: SpinBox
 var _pos_z: SpinBox
@@ -27,6 +28,7 @@ var _scale_z: SpinBox
 # Metadata
 var _name_edit: LineEdit
 var _asset_label: Label
+var _btn_delete: Button
 
 
 func _init() -> void:
@@ -83,27 +85,40 @@ func _build_ui() -> void:
 
 	# Transform header
 	var t_header := Label.new()
-	t_header.text = "Transform"
+	t_header.text = "\nTransform (3D Space)"
 	t_header.add_theme_font_size_override("font_size", 11)
 	t_header.add_theme_color_override("font_color", Color(0.35, 0.85, 1.0))
 	_content_vbox.add_child(t_header)
 
 	_pos_x = _add_spin("Pos X", _on_pos_changed)
-	_pos_y = _add_spin("Pos Y", _on_pos_changed)
+	_pos_y = _add_spin("Pos Y (Up)", _on_pos_changed, -50.0, 500.0, 0.5)
 	_pos_z = _add_spin("Pos Z", _on_pos_changed)
 
-	_rot_y = _add_spin("Yaw (°)", _on_rot_changed, -360.0, 360.0, 1.0)
+	_rot_y = _add_spin("Yaw (°)", _on_rot_changed, -360.0, 360.0, 15.0)
 
-	_scale_x = _add_spin("Scale X", _on_scale_changed, 0.05, 50.0, 0.1)
+	_scale_x = _add_spin("Scale X", _on_scale_changed, 0.1, 50.0, 0.1)
-	_scale_y = _add_spin("Scale Y", _on_scale_changed, 0.05, 50.0, 0.1)
+	_scale_y = _add_spin("Scale Y", _on_scale_changed, 0.1, 50.0, 0.1)
-	_scale_z = _add_spin("Scale Z", _on_scale_changed, 0.05, 50.0, 0.1)
+	_scale_z = _add_spin("Scale Z", _on_scale_changed, 0.1, 50.0, 0.1)
+
+	# Actions
+	var act_sep := HSeparator.new()
+	_content_vbox.add_child(act_sep)
+
+	_btn_delete = Button.new()
+	_btn_delete.text = "🗑 Delete Object"
+	_btn_delete.add_theme_color_override("font_color", Color(1.0, 0.4, 0.4))
+	_btn_delete.pressed.connect(func():
+		if _selected_id != "":
+			delete_requested.emit(_selected_id)
+	)
+	_content_vbox.add_child(_btn_delete)
 
 
 func _add_spin(label: String, callback: Callable, min_val: float = -500.0, max_val: float = 500.0, step: float = 0.5) -> SpinBox:
 	var row := HBoxContainer.new()
 	var lbl := Label.new()
 	lbl.text = label + ":"
-	lbl.custom_minimum_size = Vector2(70, 0)
+	lbl.custom_minimum_size = Vector2(80, 0)
 	lbl.add_theme_font_size_override("font_size", 10)
 	row.add_child(lbl)
 
@@ -118,6 +133,18 @@ func _add_spin(label: String, callback: Callable, min_val: float = -500.0, max_v
 	return spin
 
 
+func set_transform_values(godot_pos: Vector3, yaw_deg: float, godot_scale: Vector3) -> void:
+	_updating = true
+	if _pos_x: _pos_x.value = godot_pos.x
+	if _pos_y: _pos_y.value = godot_pos.y
+	if _pos_z: _pos_z.value = godot_pos.z
+	if _rot_y: _rot_y.value = yaw_deg
+	if _scale_x: _scale_x.value = godot_scale.x
+	if _scale_y: _scale_y.value = godot_scale.y
+	if _scale_z: _scale_z.value = godot_scale.z
+	_updating = false
+
+
 func _on_selection_changed(obj_id: String) -> void:
 	_selected_id = obj_id
 	if _selected_id == "" or _core == null:
@@ -141,16 +168,18 @@ func _on_selection_changed(obj_id: String) -> void:
 	_name_edit.text = dname
 	_asset_label.text = "Asset: %s" % obj.asset_id
 
-	_pos_x.value = obj.position.x
+	# Map chunk coords (X, Y_ground, Z_height) to Godot 3D (X, Y_height, Z_depth)
-	_pos_y.value = obj.position.y
+	var godot_pos := Vector3(obj.position.x, obj.position.z, obj.position.y)
-	_pos_z.value = obj.position.z
+	_pos_x.value = godot_pos.x
+	_pos_y.value = godot_pos.y
+	_pos_z.value = godot_pos.z
 
-	var euler = Quaternion(obj.rotation.x, obj.rotation.y, obj.rotation.z, obj.rotation.w).get_euler()
+	var euler = Quaternion(obj.rotation.x, obj.rotation.z, obj.rotation.y, obj.rotation.w).get_euler()
 	_rot_y.value = rad_to_deg(euler.y)
 
 	_scale_x.value = obj.scale.x
-	_scale_y.value = obj.scale.y
+	_scale_y.value = obj.scale.z
-	_scale_z.value = obj.scale.z
+	_scale_z.value = obj.scale.y
 	_updating = false
 
 
@@ -164,23 +193,29 @@ func _on_name_changed(new_name: String) -> void:
 func _on_pos_changed(_val: float) -> void:
 	if _updating or _core == null or _selected_id == "":
 		return
-	var new_pos := Vector3(_pos_x.value, _pos_y.value, _pos_z.value)
+	var godot_pos := Vector3(_pos_x.value, _pos_y.value, _pos_z.value)
-	_core.move_object(_selected_id, new_pos)
+	# Convert Godot 3D (X, Y_up, Z_depth) to Chunk (X, Y_ground, Z_height)
-	property_changed.emit(_selected_id, "position", new_pos)
+	var chunk_pos := Vector3(godot_pos.x, godot_pos.z, godot_pos.y)
+	_core.move_object(_selected_id, chunk_pos)
+	property_changed.emit(_selected_id, "position", godot_pos)
 
 
 func _on_rot_changed(_val: float) -> void:
 	if _updating or _core == null or _selected_id == "":
 		return
-	var quat := Quaternion.from_euler(Vector3(0, deg_to_rad(_rot_y.value), 0))
+	var deg := _rot_y.value
-	var rot_vec := Vector4(quat.x, quat.y, quat.z, quat.w)
+	var godot_q := Quaternion(Vector3.UP, deg_to_rad(deg))
+	# Convert to chunk rotation quat
+	var chunk_q := Quaternion(godot_q.x, godot_q.z, godot_q.y, godot_q.w)
+	var rot_vec := Vector4(chunk_q.x, chunk_q.y, chunk_q.z, chunk_q.w)
 	_core.rotate_object(_selected_id, rot_vec)
-	property_changed.emit(_selected_id, "rotation", rot_vec)
+	property_changed.emit(_selected_id, "rotation", godot_q)
 
 
 func _on_scale_changed(_val: float) -> void:
 	if _updating or _core == null or _selected_id == "":
 		return
-	var new_scale := Vector3(_scale_x.value, _scale_y.value, _scale_z.value)
+	var godot_scale := Vector3(_scale_x.value, _scale_y.value, _scale_z.value)
-	_core.scale_object(_selected_id, new_scale)
+	var chunk_scale := Vector3(godot_scale.x, godot_scale.z, godot_scale.y)
-	property_changed.emit(_selected_id, "scale", new_scale)
+	_core.scale_object(_selected_id, chunk_scale)
+	property_changed.emit(_selected_id, "scale", godot_scale)

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:
+		if mb.button_index == MOUSE_BUTTON_LEFT:
-			var hit_obj := _raycast_find_object(mb.position)
+			if mb.pressed:
-			if hit_obj != null:
+				_handle_left_press(mb)
-				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
 			else:
-				core.select_object("")
+				_handle_left_release(mb)
-				_status_bar_label.text = "Deselected | Click an object or [+ Add] to build"
+
+	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)
+	var obj_node := _world_container.get_node_or_null(obj_id)
-	if obj_node is Node3D:
+	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)
 

scripts/studio/studio_simulation_manager.gd

@@ -132,9 +132,18 @@ func _spawn_test_avatar() -> void:
 		_spawned_avatar = p
 
 
+func _physics_process(_delta: float) -> void:
+	if state == SimulationState.PLAYING and _spawned_avatar != null and is_instance_valid(_spawned_avatar):
+		if _spawned_avatar is Node3D and (_spawned_avatar as Node3D).global_position.y < -30.0:
+			(_spawned_avatar as Node3D).global_position = Vector3(0, 1.5, 0)
+			if _spawned_avatar is CharacterBody3D:
+				(_spawned_avatar as CharacterBody3D).velocity = Vector3.ZERO
+
+
 func is_playing() -> bool:
 	return state == SimulationState.PLAYING
 
 
 func is_editing() -> bool:
 	return state == SimulationState.EDIT
+