Category: Core
AStar class representation that uses vectors as edges.
float | _compute_cost ( int from_id, int to_id ) virtual |
float | _estimate_cost ( int from_id, int to_id ) virtual |
void | add_point ( int id, Vector3 position, float weight_scale=1.0 ) |
bool | are_points_connected ( int id, int to_id ) const |
void | clear ( ) |
void | connect_points ( int id, int to_id, bool bidirectional=true ) |
void | disconnect_points ( int id, int to_id ) |
int | get_available_point_id ( ) const |
int | get_closest_point ( Vector3 to_position ) const |
Vector3 | get_closest_position_in_segment ( Vector3 to_position ) const |
PoolIntArray | get_id_path ( int from_id, int to_id ) |
PoolIntArray | get_point_connections ( int id ) |
PoolVector3Array | get_point_path ( int from_id, int to_id ) |
Vector3 | get_point_position ( int id ) const |
float | get_point_weight_scale ( int id ) const |
Array | get_points ( ) |
bool | has_point ( int id ) const |
void | remove_point ( int id ) |
void | set_point_position ( int id, Vector3 position ) |
void | set_point_weight_scale ( int id, float weight_scale ) |
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 AStar.add_point and create segments manually with AStar.connect_points. So you can test if there is a path between two points with the AStar.are_points_connected function, get the list of existing ids in the found path with AStar.get_id_path, or the points list with AStar.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 as = AStar.new() as.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.
var as = AStar.new() as.add_point(1, Vector3(1,1,0)) as.add_point(2, Vector3(0,5,0)) as.connect_points(1, 2, false) # If bidirectional=false it's only possible to go from point 1 to point 2 # and not from point 2 to point 1.
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 as = AStar.new() as.add_point(1, Vector3(0,0,0)) as.add_point(2, Vector3(0,5,0)) as.connect_points(1, 2) var res = as.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 as = AStar.new() as.add_point(1, Vector3(0,0,0)) as.add_point(2, Vector3(0,1,0), 1) # default weight is 1 as.add_point(3, Vector3(1,1,0)) as.add_point(4, Vector3(2,0,0)) as.connect_points(1, 2, false) as.connect_points(2, 3, false) as.connect_points(4, 3, false) as.connect_points(1, 4, false) as.connect_points(5, 4, false) var res = as.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 as = AStar.new() as.add_point(1, Vector3(0,0,0)) as.add_point(2, Vector3(0,1,0)) as.add_point(3, Vector3(1,1,0)) as.add_point(4, Vector3(2,0,0)) as.connect_points(1, 2, true) as.connect_points(1, 3, true) var neighbors = as.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.
Removes the point associated with the given id from the points pool.
Sets the position for the point with the given id.
Sets the weight_scale
for the point with the given id.
© 2014–2018 Juan Linietsky, Ariel Manzur, Godot Engine contributors
Licensed under the MIT License.
http://docs.godotengine.org/en/3.0/classes/class_astar.html