Node¶
Inherits: Object
Inherited By: Viewport, Timer, CanvasLayer, EventPlayer, SoundRoomParams, Tween, Spatial, AnimationPlayer, EditorPlugin, ResourcePreloader, AnimationTreePlayer, SamplePlayer, InstancePlaceholder, HTTPRequest, StreamPlayer, CanvasItem
Category: Core
Brief Description¶
Base class for all the scene elements.
Member Functions¶
Numeric Constants¶
- NOTIFICATION_ENTER_TREE = 10
- NOTIFICATION_EXIT_TREE = 11
- NOTIFICATION_MOVED_IN_PARENT = 12
- NOTIFICATION_READY = 13
- NOTIFICATION_FIXED_PROCESS = 16
- NOTIFICATION_PROCESS = 17 — Notification received every frame when the process flag is set (see set_process).
- NOTIFICATION_PARENTED = 18 — Notification received when a node is set as a child of another node. Note that this doesn’t mean that a node entered the Scene Tree.
- NOTIFICATION_UNPARENTED = 19 — Notification received when a node is unparented (parent removed it from the list of children).
- NOTIFICATION_PAUSED = 14
- NOTIFICATION_UNPAUSED = 15
- NOTIFICATION_INSTANCED = 20
- NOTIFICATION_DRAG_BEGIN = 21
- NOTIFICATION_DRAG_END = 22
- NOTIFICATION_PATH_CHANGED = 23
- NOTIFICATION_TRANSLATION_CHANGED = 24
- NOTIFICATION_INTERNAL_PROCESS = 25
- NOTIFICATION_INTERNAL_FIXED_PROCESS = 26
- RPC_MODE_DISABLED = 0
- RPC_MODE_REMOTE = 1
- RPC_MODE_SYNC = 2
- RPC_MODE_MASTER = 3
- RPC_MODE_SLAVE = 4
- PAUSE_MODE_INHERIT = 0
- PAUSE_MODE_STOP = 1
- PAUSE_MODE_PROCESS = 2
- DUPLICATE_SIGNALS = 1
- DUPLICATE_GROUPS = 2
- DUPLICATE_SCRIPTS = 4
Description¶
Nodes are the base bricks with which Godot games are developed. They can be set as children of other nodes, resulting in a tree arrangement. A given node can contain any number of nodes as children (but there is only one scene tree root node) with the requirement that all siblings (direct children of a node) should have unique names.
Any tree of nodes is called a scene. Scenes can be saved to the disk and then instanced into other scenes. This allows for very high flexibility in the architecture and data model of the projects. Nodes can optionally be added to groups. This makes it easy to reach a number of nodes from the code (for example an “enemies” group) to perform grouped actions.
Scene tree: The SceneTree contains the active tree of nodes. When a node is added to the scene tree, it receives the NOTIFICATION_ENTER_TREE notification and its _enter_tree callback is triggered. Children nodes are always added after their parent node, i.e. the _enter_tree callback of a parent node will be triggered before its child’s.
Once all nodes have been added in the scene tree, they receive the NOTIFICATION_READY notification and their respective _ready callbacks are triggered. For groups of nodes, the _ready callback is called in reverse order, from the children up to the parent nodes.
It means that when adding a scene to the scene tree, the following order will be used for the callbacks: _enter_tree of the parent, _enter_tree of the children, _ready of the children and finally _ready of the parent (and that recursively for the whole scene).
Processing: Nodes can be set to the “process” state, so that they receive a callback on each frame requesting them to process (do something). Normal processing (callback _process, toggled with set_process) happens as fast as possible and is dependent on the frame rate, so the processing time delta is variable. Fixed processing (callback _fixed_process, toggled with set_fixed_process) happens a fixed amount of times per second (by default 60) and is useful to link itself to the physics.
Nodes can also process input events. When set, the _input function will be called for each input that the program receives. In many cases, this can be overkill (unless used for simple projects), and the _unhandled_input function might be preferred; it is called when the input event was not handled by anyone else (typically, GUI Control nodes), ensuring that the node only receives the events that were meant for it.
To keep track of the scene hierarchy (especially when instancing scenes into other scenes), an “owner” can be set for the node with set_owner. This keeps track of who instanced what. This is mostly useful when writing editors and tools, though.
Finally, when a node is freed with free or queue_free, it will also free all its children.
Networking with nodes: After connecting to a server (or making one, see NetworkedMultiplayerENet) it is possible to use the built-in RPC (remote procedure call) system to easily communicate over the network. By calling rpc with a method name, it will be called locally, and in all connected peers (peers = clients and the server that accepts connections), with behaviour varying depending on the network mode (set_network_mode) on the receiving peer. To identify which Node receives the RPC call Godot will use its NodePath (make sure node names are the same on all peers).
Member Function Description¶
- void _enter_tree ( ) virtual
Called when the node enters the SceneTree (e.g. upon instancing, scene changing or after calling add_child in a script). If the node has children, its _enter_tree callback will be called first, and then that of the children.
Corresponds to the NOTIFICATION_ENTER_TREE notification in Object._notification.
- void _exit_tree ( ) virtual
Called when the node leaves the SceneTree (e.g. upon freeing, scene changing or after calling remove_child in a script). If the node has children, its _exit_tree callback will be called last, after all its children have left the tree.
Corresponds to the NOTIFICATION_EXIT_TREE notification in Object._notification.
- void _fixed_process ( float delta ) virtual
Called during the fixed processing step of the main loop. Fixed processing means that the frame rate is synced to the physics, i.e. the delta variable should be constant.
It is only called if fixed processing has been enabled with set_fixed_process.
Corresponds to the NOTIFICATION_FIXED_PROCESS notification in Object._notification.
- void _input ( InputEvent event ) virtual
- void _process ( float delta ) virtual
Called during the processing step of the main loop. Processing happens at every frame and as fast as possible, so the delta time since the previous frame is not constant.
It is only called if processing has been enabled with set_process.
Corresponds to the NOTIFICATION_PROCESS notification in Object._notification.
- void _ready ( ) virtual
Called when the node is “ready”, i.e. when both the node and its children have entered the scene tree. If the node has children, their _ready callback gets triggered first, and the node will receive the ready notification only afterwards.
Corresponds to the NOTIFICATION_READY notification in Object._notification.
- void _unhandled_input ( InputEvent event ) virtual
- void _unhandled_key_input ( InputEventKey event ) virtual
Add a child Node. Nodes can have as many children as they want, but every child must have a unique name. Children nodes are automatically deleted when the parent node is deleted, so deleting a whole scene is performed by deleting its topmost node.
The optional boolean argument enforces creating child nodes with human-readable names, based on the name of the node being instanced instead of its type only.
Add a node to a group. Groups are helpers to name and organize a subset of nodes, like for example “enemies” or “collectables”. A Node can be in any number of groups. Nodes can be assigned a group at any time, but will not be added to it until they are inside the scene tree (see is_inside_tree).
- bool can_process ( ) const
Return true if the node can process, i.e. whether its pause mode allows processing while the scene tree is paused (see set_pause_mode). Always returns true if the scene tree is not paused, and false if the node is not in the tree. FIXME: Why FAIL_COND?
Duplicate the node, returning a new Node. If use_instancing is true, the duplicated node will be a new instance of the original PackedScene, if not it will be an independent node.
The flags are used to define what attributes (groups, signals, scripts) should be duplicated, as specified by the DUPLICATE_* constants. The default value is all of them.
Find a descendant of this node whose name matches mask as in String.match (i.e. case sensitive, but ‘*’ matches zero or more characters and ‘?’ matches any single character except ‘.’). Note that it does not match against the full path, just against individual node names.
Return a child node by its index (see get_child_count). This method is often used for iterating all children of a node.
- int get_child_count ( ) const
Return the amount of child nodes.
- Array get_children ( ) const
Return an array of references (Node) to the child nodes.
- String get_filename ( ) const
Return a filename that may be contained by the node. When a scene is instanced from a file, it topmost node contains the filename from where it was loaded (see set_filename).
- float get_fixed_process_delta_time ( ) const
Return the time elapsed since the last fixed frame (see _fixed_process). This is always the same in fixed processing unless the frames per second is changed in OS.
- Array get_groups ( ) const
Return an array listing the groups that the node is part of.
- int get_index ( ) const
Get the node index, i.e. its position among the siblings of its parent.
- String get_name ( ) const
Return the name of the node. This name is unique among the siblings (other child nodes from the same parent).
- int get_network_master ( ) const
Fetch a node. The NodePath must be valid (or else an error will be raised) and can be either the path to child node, a relative path (from the current node to another node), or an absolute path to a node.
Note: fetching absolute paths only works when the node is inside the scene tree (see is_inside_tree).
Example: Assume your current node is Character and the following tree:
/root
/root/Character
/root/Character/Sword
/root/Character/Backpack/Dagger
/root/MyGame
/root/Swamp/Alligator
/root/Swamp/Mosquito
/root/Swamp/Goblin
Possible paths are:
get_node("Sword")
get_node("Backpack/Dagger")
get_node("../Swamp/Alligator")
get_node("/root/MyGame")
- Node get_owner ( ) const
Get the node owner (see set_owner).
- Node get_parent ( ) const
Return the parent node of the current node, or an empty Node if the node lacks a parent.
- NodePath get_path ( ) const
Return the absolute path of the current node. This only works if the current node is inside the scene tree (see is_inside_tree).
Return the relative path from the current node to the specified node in “node” argument. Both nodes must be in the same scene, or else the function will fail.
- int get_pause_mode ( ) const
- int get_position_in_parent ( ) const
- float get_process_delta_time ( ) const
Return the time elapsed (in seconds) since the last process callback. This is almost always different each time.
- bool get_scene_instance_load_placeholder ( ) const
- SceneTree get_tree ( ) const
- Viewport get_viewport ( ) const
Return true if the “node” argument is a direct or indirect child of the current node, otherwise return false.
- bool is_displayed_folded ( ) const
- bool is_fixed_processing ( ) const
Return true if fixed processing is enabled (see set_fixed_process).
- bool is_fixed_processing_internal ( ) const
Return true if “node” occurs later in the scene hierarchy than the current node, otherwise return false.
- bool is_inside_tree ( ) const
- bool is_network_master ( ) const
- bool is_processing ( ) const
Return whether processing is enabled in the current node (see set_process).
- bool is_processing_input ( ) const
Return true if the node is processing input (see set_process_input).
- bool is_processing_internal ( ) const
- bool is_processing_unhandled_input ( ) const
Return true if the node is processing unhandled input (see set_process_unhandled_input).
- bool is_processing_unhandled_key_input ( ) const
Move a child node to a different position (order) amongst the other children. Since calls, signals, etc are performed by tree order, changing the order of children nodes may be useful.
- void print_stray_nodes ( )
- void print_tree ( )
Print the scene to stdout. Used mainly for debugging purposes.
Calls the method (if present) with the arguments given in “args” on this Node and recursively on all children. If the parent_first argument is true then the method will be called on the current Node first, then on all children. If it is false then the children will get called first.
- void propagate_notification ( int what )
Notify the current node and all its children recursively by calling notification() in all of them.
- void queue_free ( )
- void raise ( )
Move this node to the top of the array of nodes of the parent node. This is often useful on GUIs (Control), because their order of drawing fully depends on their order in the tree.
- void remove_and_skip ( )
Remove a node and set all its children as children of the parent node (if exists). All even subscriptions that pass by the removed node will be unsubscribed.
- void remove_child ( Node node )
Remove a child Node. Node is NOT deleted and will have to be deleted manually.
- void remove_from_group ( String group )
Remove a node from a group.
Replace a node in a scene by a given one. Subscriptions that pass through this node will be lost.
- void request_ready ( )
Send a remote procedure call request to all peers on the network (and locally), optionally sending additional data as arguments. Call request will be received by nodes with the same NodePath.
Change the method’s RPC mode (one of RPC_MODE_* constants).
Send a rpc to a specific peer identified by peer_id.
Send a rpc using an unreliable protocol.
Send a rpc to a specific peer identified by peer_id using an unreliable protocol.
Remotely change property’s value on other peers (and locally).
Change the property’s RPC mode (one of RPC_MODE_* constants).
Remotely change property’s value on a specific peer identified by peer_id.
Remotely change property’s value on other peers (and locally) using an unreliable protocol.
Remotely change property’s value on a specific peer identified by peer_id using an unreliable protocol.
- void set_display_folded ( bool fold )
- void set_filename ( String filename )
A node can contain a filename. This filename should not be changed by the user, unless writing editors and tools. When a scene is instanced from a file, it topmost node contains the filename from where it was loaded.
- void set_fixed_process ( bool enable )
Enables or disables node fixed framerate processing. When a node is being processed, it will receive a NOTIFICATION_PROCESS at a fixed (usually 60 fps, check OS to change that) interval (and the _fixed_process callback will be called if exists). It is common to check how much time was elapsed since the previous frame by calling get_fixed_process_delta_time.
- void set_fixed_process_internal ( bool enable )
- void set_name ( String name )
Set the name of the Node. Name must be unique within parent, and setting an already existing name will cause for the node to be automatically renamed.
- void set_owner ( Node owner )
Set the node owner. A node can have any other node as owner (as long as a valid parent, grandparent, etc ascending in the tree). When saving a node (using SceneSaver) all the nodes it owns will be saved with it. This allows to create complex SceneTrees, with instancing and subinstancing.
- void set_pause_mode ( int mode )
- void set_process ( bool enable )
Enables or disables node processing. When a node is being processed, it will receive a NOTIFICATION_PROCESS on every drawn frame (and the _process callback will be called if exists). It is common to check how much time was elapsed since the previous frame by calling get_process_delta_time.
- void set_process_input ( bool enable )
Enable input processing for node. This is not required for GUI controls! It hooks up the node to receive all input (see _input).
- void set_process_internal ( bool enable )
- void set_process_unhandled_input ( bool enable )
Enable unhandled input processing for node. This is not required for GUI controls! It hooks up the node to receive all input that was not previously handled before (usually by a Control). (see _unhandled_input).
- void set_process_unhandled_key_input ( bool enable )
- void set_scene_instance_load_placeholder ( bool load_placeholder )