Description

A 2D agent used to pathfind to a position while avoiding static and dynamic obstacles. The calculation can be used by the parent node to dynamically move it along the path. Requires navigation data to work correctly.

Dynamic obstacles are avoided using RVO collision avoidance. Avoidance is computed before physics, so the pathfinding information can be used safely in the physics step.

Note: After setting thetarget_position property, theget_next_path_position() method must be used once every physics frame to update the internal path logic of the navigation agent. The vector position it returns should be used as the next movement position for the agent's parent node.

Tutorials

• Using NavigationAgents

Properties

Methods

Signals

link_reached(details:Dictionary)🔗

Signals that the agent reached a navigation link. Emitted when the agent moves withinpath_desired_distance of the next position of the path when that position is a navigation link.

The details dictionary may contain the following keys depending on the value ofpath_metadata_flags:

• position: The start position of the link that was reached.

• type: AlwaysNavigationPathQueryResult2D.PATH_SEGMENT_TYPE_LINK.

• rid: TheRID of the link.

• owner: The object which manages the link (usuallyNavigationLink2D).

• link_entry_position: Ifowner is available and the owner is aNavigationLink2D, it will contain the global position of the link's point the agent is entering.

• link_exit_position: Ifowner is available and the owner is aNavigationLink2D, it will contain the global position of the link's point which the agent is exiting.

navigation_finished()🔗

Signals that the agent's navigation has finished. If the target is reachable, navigation ends when the target is reached. If the target is unreachable, navigation ends when the last waypoint of the path is reached. This signal is emitted only once per loaded path.

This signal will be emitted just aftertarget_reached when the target is reachable.

path_changed()🔗

Emitted when the agent had to update the loaded path:

• because path was previously empty.

• because navigation map has changed.

• because agent pushed further away from the current path segment than thepath_max_distance.

target_reached()🔗

Signals that the agent reached the target, i.e. the agent moved withintarget_desired_distance of thetarget_position. This signal is emitted only once per loaded path.

This signal will be emitted just beforenavigation_finished when the target is reachable.

It may not always be possible to reach the target but it should always be possible to reach the final position. Seeget_final_position().

velocity_computed(safe_velocity:Vector2)🔗

Notifies when the collision avoidance velocity is calculated. Emitted every update as long asavoidance_enabled istrue and the agent has a navigation map.

waypoint_reached(details:Dictionary)🔗

Signals that the agent reached a waypoint. Emitted when the agent moves withinpath_desired_distance of the next position of the path.

The details dictionary may contain the following keys depending on the value ofpath_metadata_flags:

• position: The position of the waypoint that was reached.

• type: The type of navigation primitive (region or link) that contains this waypoint.

• rid: TheRID of the containing navigation primitive (region or link).

• owner: The object which manages the containing navigation primitive (region or link).

Property Descriptions

boolavoidance_enabled =false🔗

• voidset_avoidance_enabled(value:bool)

• boolget_avoidance_enabled()

Iftrue the agent is registered for an RVO avoidance callback on theNavigationServer2D. Whenvelocity is used and the processing is completed asafe_velocity Vector2 is received with a signal connection tovelocity_computed. Avoidance processing with many registered agents has a significant performance cost and should only be enabled on agents that currently require it.

intavoidance_layers =1🔗

• voidset_avoidance_layers(value:int)

• intget_avoidance_layers()

A bitfield determining the avoidance layers for this NavigationAgent. Other agents with a matching bit on theavoidance_mask will avoid this agent.

intavoidance_mask =1🔗

• voidset_avoidance_mask(value:int)

• intget_avoidance_mask()

A bitfield determining what other avoidance agents and obstacles this NavigationAgent will avoid when a bit matches at least one of theiravoidance_layers.

floatavoidance_priority =1.0🔗

• voidset_avoidance_priority(value:float)

• floatget_avoidance_priority()

The agent does not adjust the velocity for other agents that would match theavoidance_mask but have a loweravoidance_priority. This in turn makes the other agents with lower priority adjust their velocities even more to avoid collision with this agent.

booldebug_enabled =false🔗

• voidset_debug_enabled(value:bool)

• boolget_debug_enabled()

Iftrue shows debug visuals for this agent.

Colordebug_path_custom_color =Color(1,1,1,1)🔗

• voidset_debug_path_custom_color(value:Color)

• Colorget_debug_path_custom_color()

Ifdebug_use_custom istrue uses this color for this agent instead of global color.

floatdebug_path_custom_line_width =-1.0🔗

• voidset_debug_path_custom_line_width(value:float)

• floatget_debug_path_custom_line_width()

Ifdebug_use_custom istrue uses this line width for rendering paths for this agent instead of global line width.

floatdebug_path_custom_point_size =4.0🔗

• voidset_debug_path_custom_point_size(value:float)

• floatget_debug_path_custom_point_size()

Ifdebug_use_custom istrue uses this rasterized point size for rendering path points for this agent instead of global point size.

booldebug_use_custom =false🔗

• voidset_debug_use_custom(value:bool)

• boolget_debug_use_custom()

Iftrue uses the defineddebug_path_custom_color for this agent instead of global color.

intmax_neighbors =10🔗

• voidset_max_neighbors(value:int)

• intget_max_neighbors()

The maximum number of neighbors for the agent to consider.

floatmax_speed =100.0🔗

• voidset_max_speed(value:float)

• floatget_max_speed()

The maximum speed that an agent can move.

intnavigation_layers =1🔗

• voidset_navigation_layers(value:int)

• intget_navigation_layers()

A bitfield determining which navigation layers of navigation regions this agent will use to calculate a path. Changing it during runtime will clear the current navigation path and generate a new one, according to the new navigation layers.

floatneighbor_distance =500.0🔗

• voidset_neighbor_distance(value:float)

• floatget_neighbor_distance()

The distance to search for other agents.

floatpath_desired_distance =20.0🔗

• voidset_path_desired_distance(value:float)

• floatget_path_desired_distance()

The distance threshold before a path point is considered to be reached. This allows agents to not have to hit a path point on the path exactly, but only to reach its general area. If this value is set too high, the NavigationAgent will skip points on the path, which can lead to it leaving the navigation mesh. If this value is set too low, the NavigationAgent will be stuck in a repath loop because it will constantly overshoot the distance to the next point on each physics frame update.

floatpath_max_distance =100.0🔗

• voidset_path_max_distance(value:float)

• floatget_path_max_distance()

The maximum distance the agent is allowed away from the ideal path to the final position. This can happen due to trying to avoid collisions. When the maximum distance is exceeded, it recalculates the ideal path.

BitField[PathMetadataFlags]path_metadata_flags =7🔗

• voidset_path_metadata_flags(value:BitField[PathMetadataFlags])

• BitField[PathMetadataFlags]get_path_metadata_flags()

Additional information to return with the navigation path.

PathPostProcessingpath_postprocessing =0🔗

• voidset_path_postprocessing(value:PathPostProcessing)

• PathPostProcessingget_path_postprocessing()

The path postprocessing applied to the raw path corridor found by thepathfinding_algorithm.

PathfindingAlgorithmpathfinding_algorithm =0🔗

• voidset_pathfinding_algorithm(value:PathfindingAlgorithm)

• PathfindingAlgorithmget_pathfinding_algorithm()

The pathfinding algorithm used in the path query.

floatradius =10.0🔗

• voidset_radius(value:float)

• floatget_radius()

The radius of the avoidance agent. This is the "body" of the avoidance agent and not the avoidance maneuver starting radius (which is controlled byneighbor_distance).

Does not affect normal pathfinding. To change an actor's pathfinding radius bakeNavigationMesh resources with a differentNavigationMesh.agent_radius property and use different navigation maps for each actor size.

floatsimplify_epsilon =0.0🔗

• voidset_simplify_epsilon(value:float)

• floatget_simplify_epsilon()

The path simplification amount in worlds units.

boolsimplify_path =false🔗

• voidset_simplify_path(value:bool)

• boolget_simplify_path()

Iftrue a simplified version of the path will be returned with less critical path points removed. The simplification amount is controlled bysimplify_epsilon. The simplification uses a variant of Ramer-Douglas-Peucker algorithm for curve point decimation.

Path simplification can be helpful to mitigate various path following issues that can arise with certain agent types and script behaviors. E.g. "steering" agents or avoidance in "open fields".

floattarget_desired_distance =10.0🔗

• voidset_target_desired_distance(value:float)

• floatget_target_desired_distance()

The distance threshold before the target is considered to be reached. On reaching the target,target_reached is emitted and navigation ends (seeis_navigation_finished() andnavigation_finished).

You can make navigation end early by setting this property to a value greater thanpath_desired_distance (navigation will end before reaching the last waypoint).

You can also make navigation end closer to the target than each individual path position by setting this property to a value lower thanpath_desired_distance (navigation won't immediately end when reaching the last waypoint). However, if the value set is too low, the agent will be stuck in a repath loop because it will constantly overshoot the distance to the target on each physics frame update.

Vector2target_position =Vector2(0,0)🔗

• voidset_target_position(value:Vector2)

• Vector2get_target_position()

If set, a new navigation path from the current agent position to thetarget_position is requested from the NavigationServer.

floattime_horizon_agents =1.0🔗

• voidset_time_horizon_agents(value:float)

• floatget_time_horizon_agents()

The minimal amount of time for which this agent's velocities, that are computed with the collision avoidance algorithm, are safe with respect to other agents. The larger the number, the sooner the agent will respond to other agents, but less freedom in choosing its velocities. A too high value will slow down agents movement considerably. Must be positive.

floattime_horizon_obstacles =0.0🔗

• voidset_time_horizon_obstacles(value:float)

• floatget_time_horizon_obstacles()

The minimal amount of time for which this agent's velocities, that are computed with the collision avoidance algorithm, are safe with respect to static avoidance obstacles. The larger the number, the sooner the agent will respond to static avoidance obstacles, but less freedom in choosing its velocities. A too high value will slow down agents movement considerably. Must be positive.

Vector2velocity =Vector2(0,0)🔗

• voidset_velocity(value:Vector2)

• Vector2get_velocity()

Sets the new wanted velocity for the agent. The avoidance simulation will try to fulfill this velocity if possible but will modify it to avoid collision with other agents and obstacles. When an agent is teleported to a new position, useset_velocity_forced() as well to reset the internal simulation velocity.

Method Descriptions

floatdistance_to_target()const🔗

Returns the distance to the target position, using the agent's global position. The user must settarget_position in order for this to be accurate.

boolget_avoidance_layer_value(layer_number:int)const🔗

Returns whether or not the specified layer of theavoidance_layers bitmask is enabled, given alayer_number between 1 and 32.

boolget_avoidance_mask_value(mask_number:int)const🔗

Returns whether or not the specified mask of theavoidance_mask bitmask is enabled, given amask_number between 1 and 32.

PackedVector2Arrayget_current_navigation_path()const🔗

Returns this agent's current path from start to finish in global coordinates. The path only updates when the target position is changed or the agent requires a repath. The path array is not intended to be used in direct path movement as the agent has its own internal path logic that would get corrupted by changing the path array manually. Use the intendedget_next_path_position() once every physics frame to receive the next path point for the agents movement as this function also updates the internal path logic.

intget_current_navigation_path_index()const🔗

Returns which index the agent is currently on in the navigation path'sPackedVector2Array.

NavigationPathQueryResult2Dget_current_navigation_result()const🔗

Returns the path query result for the path the agent is currently following.

Vector2get_final_position()🔗

Returns the reachable final position of the current navigation path in global coordinates. This position can change if the agent needs to update the navigation path which makes the agent emit thepath_changed signal.

boolget_navigation_layer_value(layer_number:int)const🔗

Returns whether or not the specified layer of thenavigation_layers bitmask is enabled, given alayer_number between 1 and 32.

RIDget_navigation_map()const🔗

Returns theRID of the navigation map for this NavigationAgent node. This function returns always the map set on the NavigationAgent node and not the map of the abstract agent on the NavigationServer. If the agent map is changed directly with the NavigationServer API the NavigationAgent node will not be aware of the map change. Useset_navigation_map() to change the navigation map for the NavigationAgent and also update the agent on the NavigationServer.

Vector2get_next_path_position()🔗

Returns the next position in global coordinates that can be moved to, making sure that there are no static objects in the way. If the agent does not have a navigation path, it will return the position of the agent's parent. The use of this function once every physics frame is required to update the internal path logic of the NavigationAgent.

RIDget_rid()const🔗

Returns theRID of this agent on theNavigationServer2D.

boolis_navigation_finished()🔗

Returnstrue if the agent's navigation has finished. If the target is reachable, navigation ends when the target is reached. If the target is unreachable, navigation ends when the last waypoint of the path is reached.

Note: Whiletrue prefer to stop calling update functions likeget_next_path_position(). This avoids jittering the standing agent due to calling repeated path updates.

boolis_target_reachable()🔗

Returnstrue ifget_final_position() is withintarget_desired_distance of thetarget_position.

boolis_target_reached()const🔗

Returnstrue if the agent reached the target, i.e. the agent moved withintarget_desired_distance of thetarget_position. It may not always be possible to reach the target but it should always be possible to reach the final position. Seeget_final_position().

voidset_avoidance_layer_value(layer_number:int, value:bool)🔗

Based onvalue, enables or disables the specified layer in theavoidance_layers bitmask, given alayer_number between 1 and 32.

voidset_avoidance_mask_value(mask_number:int, value:bool)🔗

Based onvalue, enables or disables the specified mask in theavoidance_mask bitmask, given amask_number between 1 and 32.

voidset_navigation_layer_value(layer_number:int, value:bool)🔗

Based onvalue, enables or disables the specified layer in thenavigation_layers bitmask, given alayer_number between 1 and 32.

voidset_navigation_map(navigation_map:RID)🔗

Sets theRID of the navigation map this NavigationAgent node should use and also updates theagent on the NavigationServer.

voidset_velocity_forced(velocity:Vector2)🔗

Replaces the internal velocity in the collision avoidance simulation withvelocity. When an agent is teleported to a new position this function should be used in the same frame. If called frequently this function can get agents stuck.