NavigationServer2D is the server that handles navigation maps, regions and agents. It does not handle A* navigation from [AStar2D] or [AStarGrid2D].
Maps are made up of regions, which are made of navigation polygons. Together, they define the traversable areas in the 2D world.
[b]Note:[/b] Most [NavigationServer2D] changes take effect after the next physics frame and not immediately. This includes all changes made to maps, regions or agents by navigation-related nodes in the scene tree or made through scripts.
For two regions to be connected to each other, they must share a similar edge. An edge is considered connected to another if both of its two vertices are at a distance less than [code]edge_connection_margin[/code] to the respective other edge's vertex.
You may assign navigation layers to regions with [method NavigationServer2D.region_set_navigation_layers], which then can be checked upon when requesting a path with [method NavigationServer2D.map_get_path]. This can be used to allow or deny certain areas for some objects.
To use the collision avoidance system, you may use agents. You can set an agent's target velocity, then the servers will emit a callback with a modified velocity.
[b]Note:[/b] The collision avoidance system ignores regions. Using the modified velocity directly may move an agent outside of the traversable area. This is a limitation of the collision avoidance system, any more complex situation may require the use of the physics engine.
This server keeps tracks of any call and executes them during the sync phase. This means that you can request any change to the map, using any thread, without worrying.
Sets the callback [Callable] that gets called after each avoidance processing step for the [param agent]. The calculated [code]safe_velocity[/code] will be dispatched with a signal to the object just before the physics calculations.
[b]Note:[/b] Created callbacks are always processed independently of the SceneTree state as long as the agent is on a navigation map and not freed. To disable the dispatch of a callback from an agent use [method agent_set_avoidance_callback] again with an empty [Callable].
</description>
</method>
<methodname="agent_set_avoidance_enabled">
<returntype="void"/>
<paramindex="0"name="agent"type="RID"/>
<paramindex="1"name="enabled"type="bool"/>
<description>
If [param enabled] is [code]true[/code] the specified [param agent] uses avoidance.
</description>
</method>
<methodname="agent_set_avoidance_layers">
<returntype="void"/>
<paramindex="0"name="agent"type="RID"/>
<paramindex="1"name="layers"type="int"/>
<description>
Set the agent's [code]avoidance_layers[/code] bitmask.
</description>
</method>
<methodname="agent_set_avoidance_mask">
<returntype="void"/>
<paramindex="0"name="agent"type="RID"/>
<paramindex="1"name="mask"type="int"/>
<description>
Set the agent's [code]avoidance_mask[/code] bitmask.
</description>
</method>
<methodname="agent_set_avoidance_priority">
<returntype="void"/>
<paramindex="0"name="agent"type="RID"/>
<paramindex="1"name="priority"type="float"/>
<description>
Set the agent's [code]avoidance_priority[/code] with a [param priority] between 0.0 (lowest priority) to 1.0 (highest priority).
The specified [param agent] does not adjust the velocity for other agents that would match the [code]avoidance_mask[/code] but have a lower [code] avoidance_priority[/code]. This in turn makes the other agents with lower priority adjust their velocities even more to avoid collision with this agent.
Sets the maximum number of other agents the agent takes into account in the navigation. The larger this number, the longer the running time of the simulation. If the number is too low, the simulation will not be safe.
Sets the maximum distance to other agents this agent takes into account in the navigation. The larger this number, the longer the running time of the simulation. If the number is too low, the simulation will not be safe.
The minimal amount of time for which the agent's velocities that are computed by the simulation are safe with respect to other agents. The larger this number, the sooner this agent will respond to the presence of other agents, but the less freedom this agent has in choosing its velocities. A too high value will slow down agents movement considerably. Must be positive.
The minimal amount of time for which the agent's velocities that are computed by the simulation are safe with respect to static avoidance obstacles. The larger this number, the sooner this agent will respond to the presence of static avoidance obstacles, but the less freedom this agent has in choosing its velocities. A too high value will slow down agents movement considerably. Must be positive.
Sets [param velocity] as the new wanted velocity for the specified [param agent]. The avoidance simulation will try to fulfil this velocity if possible but will modify it to avoid collision with other agent's and obstacles. When an agent is teleported to a new position far away use [method agent_set_velocity_forced] instead to reset the internal velocity state.
</description>
</method>
<methodname="agent_set_velocity_forced">
<returntype="void"/>
<paramindex="0"name="agent"type="RID"/>
<paramindex="1"name="velocity"type="Vector2"/>
<description>
Replaces the internal velocity in the collision avoidance simulation with [param velocity] for the specified [param agent]. When an agent is teleported to a new position far away this function should be used in the same frame. If called frequently this function can get agents stuck.
Returns all created navigation map [RID]s on the NavigationServer. This returns both 2D and 3D created navigation maps as there is technically no distinction between them.
This function immediately forces synchronization of the specified navigation [param map] [RID]. By default navigation maps are only synchronized at the end of each physics frame. This function can be used to immediately (re)calculate all the navigation meshes and region connections of the navigation map. This makes it possible to query a navigation path for a changed map immediately and in the same frame (multiple times if needed).
Due to technical restrictions the current NavigationServer command queue will be flushed. This means all already queued update commands for this physics frame will be executed, even those intended for other maps, regions and agents not part of the specified map. The expensive computation of the navigation meshes and region connections of a map will only be done for the specified map. Other maps will receive the normal synchronization at the end of the physics frame. Should the specified map receive changes after the forced update it will update again as well when the other maps receive their update.
Avoidance processing and dispatch of the [code]safe_velocity[/code] signals is untouched by this function and continues to happen for all maps and agents at the end of the physics frame.
[b]Note:[/b] With great power comes great responsibility. This function should only be used by users that really know what they are doing and have a good reason for it. Forcing an immediate update of a navigation map requires locking the NavigationServer and flushing the entire NavigationServer command queue. Not only can this severely impact the performance of a game but it can also introduce bugs if used inappropriately without much foresight.
Returns the navigation path to reach the destination from the origin. [param navigation_layers] is a bitmask of all region navigation layers that are allowed to be in the path.
Returns whether the navigation [param map] allows navigation regions to use edge connections to connect with other navigation regions within proximity of the navigation map edge connection margin.
Set the navigation [param map] edge connection use. If [param enabled] the navigation map allows navigation regions to use edge connections to connect with other navigation regions within proximity of the navigation map edge connection margin.
Sets [param velocity] of the dynamic [param obstacle]. Allows other agents to better predict the movement of the dynamic obstacle. Only works in combination with the radius of the obstacle.
Sets the outline vertices for the obstacle. If the vertices are winded in clockwise order agents will be pushed in by the obstacle, else they will be pushed out.
Queries a path in a given navigation map. Start and target position and other parameters are defined through [NavigationPathQueryParameters2D]. Updates the provided [NavigationPathQueryResult2D] result object with the path among other results requested by the query.
Returns the starting point of a connection door. [param connection] is an index between 0 and the return value of [method region_get_connections_count].
Returns whether the navigation [param region] is set to use edge connections to connect with other navigation regions within proximity of the navigation map edge connection margin.
Returns [code]true[/code] if the provided [param point] in world space is currently owned by the provided navigation [param region]. Owned in this context means that one of the region's navigation mesh polygon faces has a possible position at the closest distance to this point compared to all other navigation meshes from other navigation regions that are also registered on the navigation map of the provided region.
If multiple navigation meshes have positions at equal distance the navigation region whose polygons are processed first wins the ownership. Polygons are processed in the same order that navigation regions were registered on the NavigationServer.
[b]Note:[/b] If navigation meshes from different navigation regions overlap (which should be avoided in general) the result might not be what is expected.
If [param enabled] the navigation [param region] will use edge connections to connect with other navigation regions within proximity of the navigation map edge connection margin.
