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Using NavigationPaths

Obtaining a Navigationpath

Navigation paths can be directly queried from the NavigationServer and do not require any additional nodes or objects as long as the navigation map has a navigationmesh to work with.

To obtain a 2D path, use NavigationServer2D.map_get_path(map, from, to, optimize, navigation_layers).

To obtain a 3D path, use NavigationServer3D.map_get_path(map, from, to, optimize, navigation_layers).

For more customizable navigation path queries that require additional setup see Using NavigationPathQueryObjects.

One of the required parameters for the query is the RID of the navigation map. Each game World has a default navigation map automatically created. The default navigation maps can be retrieved with get_world_2d().get_navigation_map() from any Node2D inheriting node or get_world_3d().get_navigation_map() from any Node3D inheriting node. The second and third parameters are the starting position and the target position as Vector2 for 2D or Vector3 for 3D.

If the optimized parameter is true, path positions will be shortened along polygon corners with an additional funnel algorithm pass. This works well for free movement on navigationmeshes with unequal sized polygons as the path will hug around corners along the polygon corridor found by the A* algorithm. With small cells the A* algorithm creates a very narrow funnel corridor that can create ugly corner paths when used with grids.

If the optimized parameter is false, path positions will be placed at the center of each polygon edge. This works well for pure grid movement on navmeshes with equal sized polygons as the path will go through the center of the grid cells. Outside of grids due to polygons often covering large open areas with a single, long edge this can create paths with unnecessary long detours.

GDScript

extends Node2D
 # basic query for a navigation path in 2D using the default navigation map
var default_2d_map_rid: RID = get_world_2d().get_navigation_map()
var start_position: Vector2 = Vector2(0.0, 0.0)
var target_position: Vector2 = Vector2(5.0, 0.0)
var path: PackedVector2Array = NavigationServer2D.map_get_path(
    default_2d_map_rid,
    start_position,
    target_position,
    true
)

GDScript

extends Node3D
# basic query for a navigation path in 3D using the default navigation map
var default_3d_map_rid: RID = get_world_3d().get_navigation_map()
var start_position: Vector3 = Vector3(0.0, 0.0, 0.0)
var target_position: Vector3 = Vector3(5.0, 0.0, 3.0)
var path: PackedVector3Array = NavigationServer3D.map_get_path(
    default_3d_map_rid,
    start_position,
    target_position,
    true
)

A returned path by the NavigationServer will be a PackedVector2Array for 2D or a PackedVector3Array for 3D. These are just a memory-optimized Array of vector positions. All position vectors inside the array are guaranteed to be inside a NavigationPolygon or NavigationMesh. The path array, if not empty, has the navigationmesh position closest to the starting position at the first index path[0] position. The closest available navigationmesh position to the target position is the last index path[path.size()-1] position. All index between are the pathpoints that an actor should follow to reach the target without leaving the navigation mesh.

备注

If the target position is on a different navigation mesh that is not merged or connected the navigation path will lead to the closest possible position on the starting position navigation mesh.

The following script moves a Node3D inheriting node along a navigation path using the default navigation map by setting the target position with set_movement_target().

GDScript

var movement_speed: float = 4.0
var movement_delta: float
var path_point_margin: float = 0.5
var default_3d_map_rid: RID = get_world_3d().get_navigation_map()

var current_path_index: int = 0
var current_path_point: Vector3
var current_path: PackedVector3Array

func set_movement_target(target_position: Vector3):

    var start_position: Vector3 = global_transform.origin

    current_path = NavigationServer3D.map_get_path(
        default_3d_map_rid,
        start_position,
        target_position,
        true
    )

    if not current_path.is_empty():
        current_path_index = 0
        current_path_point = current_path[0]

func _physics_process(delta):

    if current_path.is_empty():
        return

    movement_delta = move_speed * delta

    if global_transform.origin.distance_to(current_path_point) <= path_point_margin:
        current_path_index += 1
        if current_path_index >= current_path.size():
            current_path = []
            current_path_index = 0
            current_path_point = global_transform.origin
            return

    current_path_point = current_path[current_path_index]

    var new_velocity: Vector3 = global_transform.origin.direction_to(current_path_point) * movement_delta

    global_transform.origin = global_transform.origin.move_toward(global_transform.origin + new_velocity, movement_delta)