**Category:** Core

AStar class representation that uses vectors as edges.

A* (A star) is a computer algorithm that is widely used in pathfinding and graph traversal, the process of plotting an efficiently directed path between multiple points. It enjoys widespread use due to its performance and accuracy. Godot’s A* implementation make use of vectors as points.

You must add points manually with add_point and create segments manually with connect_points. So you can test if there is a path between two points with the are_points_connected function, get the list of existing ids in the found path with get_id_path, or the points list with get_point_path.

Called when computing the cost between two connected points.

Called when estimating the cost between a point and the path’s ending point.

Adds a new point at the given position with the given identifier. The algorithm prefers points with lower `weight_scale`

to form a path. The `id`

must be 0 or larger, and the `weight_scale`

must be 1 or larger.

var astar = AStar.new() astar.add_point(1, Vector3(1, 0, 0), 4) # Adds the point (1, 0, 0) with weight_scale 4 and id 1

If there already exists a point for the given id, its position and weight scale are updated to the given values.

Returns whether there is a connection/segment between the given points.

Clears all the points and segments.

Creates a segment between the given points. If `bidirectional`

is `false`

, only movement from `id`

to `to_id`

is allowed, not the reverse direction.

var astar = AStar.new() astar.add_point(1, Vector3(1, 1, 0)) astar.add_point(2, Vector3(0, 5, 0)) astar.connect_points(1, 2, false)

Deletes the segment between the given points.

Returns the next available point id with no point associated to it.

Returns the id of the closest point to `to_position`

. Returns -1 if there are no points in the points pool.

Returns the closest position to `to_position`

that resides inside a segment between two connected points.

var astar = AStar.new() astar.add_point(1, Vector3(0, 0, 0)) astar.add_point(2, Vector3(0, 5, 0)) astar.connect_points(1, 2) var res = astar.get_closest_position_in_segment(Vector3(3, 3, 0)) # Returns (0, 3, 0)

The result is in the segment that goes from `y = 0`

to `y = 5`

. It’s the closest position in the segment to the given point.

Returns an array with the ids of the points that form the path found by AStar between the given points. The array is ordered from the starting point to the ending point of the path.

var astar = AStar.new() astar.add_point(1, Vector3(0, 0, 0)) astar.add_point(2, Vector3(0, 1, 0), 1) # Default weight is 1 astar.add_point(3, Vector3(1, 1, 0)) astar.add_point(4, Vector3(2, 0, 0)) astar.connect_points(1, 2, false) astar.connect_points(2, 3, false) astar.connect_points(4, 3, false) astar.connect_points(1, 4, false) var res = astar.get_id_path(1, 3) # Returns [1, 2, 3]

If you change the 2nd point’s weight to 3, then the result will be `[1, 4, 3]`

instead, because now even though the distance is longer, it’s “easier” to get through point 4 than through point 2.

Returns an array with the ids of the points that form the connect with the given point.

var astar = AStar.new() astar.add_point(1, Vector3(0, 0, 0)) astar.add_point(2, Vector3(0, 1, 0)) astar.add_point(3, Vector3(1, 1, 0)) astar.add_point(4, Vector3(2, 0, 0)) astar.connect_points(1, 2, true) astar.connect_points(1, 3, true) var neighbors = astar.get_point_connections(1) # Returns [2, 3]

Returns an array with the points that are in the path found by AStar between the given points. The array is ordered from the starting point to the ending point of the path.

Returns the position of the point associated with the given id.

Returns the weight scale of the point associated with the given id.

Returns an array of all points.

Returns whether a point associated with the given id exists.

Returns whether a point is disabled or not for pathfinding. By default, all points are enabled.

Removes the point associated with the given id from the points pool.

Disables or enables the specified point for pathfinding. Useful for making a temporary obstacle.

Sets the position for the point with the given id.

Sets the `weight_scale`

for the point with the given id.

© 2014–2019 Juan Linietsky, Ariel Manzur, Godot Engine contributors

Licensed under the MIT License.

http://docs.godotengine.org/en/3.1/classes/class_astar.html