SceneTree

Inherits: MainLoop < Object

Manages the game loop via a hierarchy of nodes.

Description

As one of the most important classes, the SceneTree manages the hierarchy of nodes in a scene as well as scenes themselves. Nodes can be added, retrieved and removed. The whole scene tree (and thus the current scene) can be paused. Scenes can be loaded, switched and reloaded.

You can also use the SceneTree to organize your nodes into groups: every node can be assigned as many groups as you want to create, e.g. a "enemy" group. You can then iterate these groups or even call methods and set properties on all the group's members at once.

SceneTree is the default MainLoop implementation used by scenes, and is thus in charge of the game loop.

Tutorials

• SceneTree
• Multiple resolutions

Properties

Node	current_scene
bool	debug_collisions_hint	false
bool	debug_navigation_hint	false
Node	edited_scene_root
MultiplayerAPI	multiplayer
bool	multiplayer_poll	true
NetworkedMultiplayerPeer	network_peer
bool	paused	false
bool	refuse_new_network_connections	false
Viewport	root
bool	use_font_oversampling	false

Methods

Variant	call_group ( String group, String method, ... ) vararg
Variant	call_group_flags ( int flags, String group, String method, ... ) vararg
Error	change_scene ( String path )
Error	change_scene_to ( PackedScene packed_scene )
SceneTreeTimer	create_timer ( float time_sec, bool pause_mode_process=true )
int	get_frame ( ) const
PoolIntArray	get_network_connected_peers ( ) const
int	get_network_unique_id ( ) const
int	get_node_count ( ) const
Array	get_nodes_in_group ( String group )
int	get_rpc_sender_id ( ) const
bool	has_group ( String name ) const
bool	has_network_peer ( ) const
bool	is_input_handled ( )
bool	is_network_server ( ) const
void	notify_group ( String group, int notification )
void	notify_group_flags ( int call_flags, String group, int notification )
void	queue_delete ( Object obj )
void	quit ( int exit_code=-1 )
Error	reload_current_scene ( )
void	set_auto_accept_quit ( bool enabled )
void	set_group ( String group, String property, Variant value )
void	set_group_flags ( int call_flags, String group, String property, Variant value )
void	set_input_as_handled ( )
void	set_quit_on_go_back ( bool enabled )
void	set_screen_stretch ( StretchMode mode, StretchAspect aspect, Vector2 minsize, float shrink=1 )

Signals

connected_to_server ( )

Emitted whenever this SceneTree's network_peer successfully connected to a server. Only emitted on clients.

connection_failed ( )

Emitted whenever this SceneTree's network_peer fails to establish a connection to a server. Only emitted on clients.

files_dropped ( PoolStringArray files, int screen )

Emitted when files are dragged from the OS file manager and dropped in the game window. The arguments are a list of file paths and the identifier of the screen where the drag originated.

global_menu_action ( Variant id, Variant meta )

Emitted whenever global menu item is clicked.

idle_frame ( )

Emitted immediately before Node._process is called on every node in the SceneTree.

network_peer_connected ( int id )

Emitted whenever this SceneTree's network_peer connects with a new peer. ID is the peer ID of the new peer. Clients get notified when other clients connect to the same server. Upon connecting to a server, a client also receives this signal for the server (with ID being 1).

network_peer_disconnected ( int id )

Emitted whenever this SceneTree's network_peer disconnects from a peer. Clients get notified when other clients disconnect from the same server.

node_added ( Node node )

Emitted whenever a node is added to the SceneTree.

node_configuration_warning_changed ( Node node )

Emitted when a node's configuration changed. Only emitted in tool mode.

node_removed ( Node node )

Emitted whenever a node is removed from the SceneTree.

node_renamed ( Node node )

Emitted whenever a node is renamed.

physics_frame ( )

Emitted immediately before Node._physics_process is called on every node in the SceneTree.

screen_resized ( )

Emitted when the screen resolution (fullscreen) or window size (windowed) changes.

server_disconnected ( )

Emitted whenever this SceneTree's network_peer disconnected from server. Only emitted on clients.

tree_changed ( )

Emitted whenever the SceneTree hierarchy changed (children being moved or renamed, etc.).

Enumerations

enum GroupCallFlags:

• GROUP_CALL_DEFAULT = 0 --- Call a group with no flags (default).
• GROUP_CALL_REVERSE = 1 --- Call a group in reverse scene order.
• GROUP_CALL_REALTIME = 2 --- Call a group immediately (calls are normally made on idle).
• GROUP_CALL_UNIQUE = 4 --- Call a group only once even if the call is executed many times.

enum StretchMode:

• STRETCH_MODE_DISABLED = 0 --- No stretching.
• STRETCH_MODE_2D = 1 --- Render stretching in higher resolution (interpolated).
• STRETCH_MODE_VIEWPORT = 2 --- Keep the specified display resolution. No interpolation. Content may appear pixelated.

enum StretchAspect:

• STRETCH_ASPECT_IGNORE = 0 --- Fill the window with the content stretched to cover excessive space. Content may appear stretched.
• STRETCH_ASPECT_KEEP = 1 --- Retain the same aspect ratio by padding with black bars on either axis. This prevents distortion.
• STRETCH_ASPECT_KEEP_WIDTH = 2 --- Expand vertically. Left/right black bars may appear if the window is too wide.
• STRETCH_ASPECT_KEEP_HEIGHT = 3 --- Expand horizontally. Top/bottom black bars may appear if the window is too tall.
• STRETCH_ASPECT_EXPAND = 4 --- Expand in both directions, retaining the same aspect ratio. This prevents distortion while avoiding black bars.

Property Descriptions

Node current_scene

Setter	set_current_scene(value)
Getter	get_current_scene()

The current scene.

bool debug_collisions_hint

Default	false
Setter	set_debug_collisions_hint(value)
Getter	is_debugging_collisions_hint()

If true, collision shapes will be visible when running the game from the editor for debugging purposes.

bool debug_navigation_hint

Default	false
Setter	set_debug_navigation_hint(value)
Getter	is_debugging_navigation_hint()

If true, navigation polygons will be visible when running the game from the editor for debugging purposes.

Node edited_scene_root

Setter	set_edited_scene_root(value)
Getter	get_edited_scene_root()

The root of the edited scene.

MultiplayerAPI multiplayer

Setter	set_multiplayer(value)
Getter	get_multiplayer()

The default MultiplayerAPI instance for this SceneTree.

bool multiplayer_poll

Default	true
Setter	set_multiplayer_poll_enabled(value)
Getter	is_multiplayer_poll_enabled()

If true (default value), enables automatic polling of the MultiplayerAPI for this SceneTree during idle_frame.

If false, you need to manually call MultiplayerAPI.poll to process network packets and deliver RPCs/RSETs. This allows running RPCs/RSETs in a different loop (e.g. physics, thread, specific time step) and for manual Mutex protection when accessing the MultiplayerAPI from threads.

NetworkedMultiplayerPeer network_peer

Setter	set_network_peer(value)
Getter	get_network_peer()

The peer object to handle the RPC system (effectively enabling networking when set). Depending on the peer itself, the SceneTree will become a network server (check with is_network_server) and will set the root node's network mode to master, or it will become a regular peer with the root node set to puppet. All child nodes are set to inherit the network mode by default. Handling of networking-related events (connection, disconnection, new clients) is done by connecting to SceneTree's signals.

bool paused

Default	false
Setter	set_pause(value)
Getter	is_paused()

If true, the SceneTree is paused. Doing so will have the following behavior:

• 2D and 3D physics will be stopped.
• Node._process, Node._physics_process and Node._input will not be called anymore in nodes.

bool refuse_new_network_connections

Default	false
Setter	set_refuse_new_network_connections(value)
Getter	is_refusing_new_network_connections()

If true, the SceneTree's network_peer refuses new incoming connections.

Viewport root

Getter

get_root()

The SceneTree's root Viewport.

bool use_font_oversampling

Default	false
Setter	set_use_font_oversampling(value)
Getter	is_using_font_oversampling()

If true, font oversampling is used.

Method Descriptions

Variant call_group ( String group, String method, ... ) vararg

Calls method on each member of the given group.

Variant call_group_flags ( int flags, String group, String method, ... ) vararg

Calls method on each member of the given group, respecting the given GroupCallFlags.

Error change_scene ( String path )

Changes the running scene to the one at the given path, after loading it into a PackedScene and creating a new instance.

Returns @GlobalScope.OK on success, @GlobalScope.ERR_CANT_OPEN if the path cannot be loaded into a PackedScene, or @GlobalScope.ERR_CANT_CREATE if that scene cannot be instantiated.

Error change_scene_to ( PackedScene packed_scene )

Changes the running scene to a new instance of the given PackedScene.

Returns @GlobalScope.OK on success or @GlobalScope.ERR_CANT_CREATE if the scene cannot be instantiated.

SceneTreeTimer create_timer ( float time_sec, bool pause_mode_process=true )

Returns a SceneTreeTimer which will SceneTreeTimer.timeout after the given time in seconds elapsed in this SceneTree. If pause_mode_process is set to false, pausing the SceneTree will also pause the timer.

Commonly used to create a one-shot delay timer as in the following example:

func some_function():
    print("start")
    yield(get_tree().create_timer(1.0), "timeout")
    print("end")

int get_frame ( ) const

Returns the current frame number, i.e. the total frame count since the application started.

PoolIntArray get_network_connected_peers ( ) const

Returns the peer IDs of all connected peers of this SceneTree's network_peer.

int get_network_unique_id ( ) const

Returns the unique peer ID of this SceneTree's network_peer.

int get_node_count ( ) const

Returns the number of nodes in this SceneTree.

Array get_nodes_in_group ( String group )

Returns a list of all nodes assigned to the given group.

int get_rpc_sender_id ( ) const

Returns the sender's peer ID for the most recently received RPC call.

bool has_group ( String name ) const

Returns true if the given group exists.

bool has_network_peer ( ) const

Returns true if there is a network_peer set.

bool is_input_handled ( )

Returns true if the most recent InputEvent was marked as handled with set_input_as_handled.

bool is_network_server ( ) const

Returns true if this SceneTree's network_peer is in server mode (listening for connections).

void notify_group ( String group, int notification )

Sends the given notification to all members of the group.

void notify_group_flags ( int call_flags, String group, int notification )

Sends the given notification to all members of the group, respecting the given GroupCallFlags.

void queue_delete ( Object obj )

Queues the given object for deletion, delaying the call to Object.free to after the current frame.

void quit ( int exit_code=-1 )

Quits the application. A process exit_code can optionally be passed as an argument. If this argument is 0 or greater, it will override the OS.exit_code defined before quitting the application.

Error reload_current_scene ( )

Reloads the currently active scene.

Returns @GlobalScope.OK on success, @GlobalScope.ERR_UNCONFIGURED if no current_scene was defined yet, @GlobalScope.ERR_CANT_OPEN if current_scene cannot be loaded into a PackedScene, or @GlobalScope.ERR_CANT_CREATE if the scene cannot be instantiated.

void set_auto_accept_quit ( bool enabled )

If true, the application automatically accepts quitting. Enabled by default.

For mobile platforms, see set_quit_on_go_back.

void set_group ( String group, String property, Variant value )

Sets the given property to value on all members of the given group.

void set_group_flags ( int call_flags, String group, String property, Variant value )

Sets the given property to value on all members of the given group, respecting the given GroupCallFlags.

void set_input_as_handled ( )

Marks the most recent InputEvent as handled.

void set_quit_on_go_back ( bool enabled )

If true, the application quits automatically on going back (e.g. on Android). Enabled by default.

To handle 'Go Back' button when this option is disabled, use MainLoop.NOTIFICATION_WM_GO_BACK_REQUEST.

void set_screen_stretch ( StretchMode mode, StretchAspect aspect, Vector2 minsize, float shrink=1 )

Configures screen stretching to the given StretchMode, StretchAspect, minimum size and shrink ratio.