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Merge pull request #98978 from tetrapod00/astar-nonsense

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Docs: Update AStar3D examples
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Rémi Verschelde
2024-12-17 22:59:25 +01:00
parent 66b8101cef c6cfed44e4
commit d4f4129dba
1 changed files with 23 additions and 10 deletions
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33
doc/classes/AStar3D.xml
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@@ -6,29 +6,42 @@
<description>
A* (A star) is a computer algorithm used in pathfinding and graph traversal, the process of plotting short paths among vertices (points), passing through a given set of edges (segments). It enjoys widespread use due to its performance and accuracy. Godot's A* implementation uses points in 3D space and Euclidean distances by default.
You must add points manually with [method add_point] and create segments manually with [method connect_points]. Once done, you can test if there is a path between two points with the [method are_points_connected] function, get a path containing indices by [method get_id_path], or one containing actual coordinates with [method get_point_path].
It is also possible to use non-Euclidean distances. To do so, create a class that extends [AStar3D] and override methods [method _compute_cost] and [method _estimate_cost]. Both take two indices and return a length, as is shown in the following example.
It is also possible to use non-Euclidean distances. To do so, create a script that extends [AStar3D] and override the methods [method _compute_cost] and [method _estimate_cost]. Both should take two point IDs and return the distance between the corresponding points.
[b]Example:[/b] Use Manhattan distance instead of Euclidean distance:
[codeblocks]
[gdscript]
class MyAStar:
extends AStar3D
class_name MyAStar3D
extends AStar3D
func _compute_cost(u, v):
return abs(u - v)
func _compute_cost(u, v):
var u_pos = get_point_position(u)
var v_pos = get_point_position(v)
return abs(u_pos.x - v_pos.x) + abs(u_pos.y - v_pos.y) + abs(u_pos.z - v_pos.z)
func _estimate_cost(u, v):
return min(0, abs(u - v) - 1)
func _estimate_cost(u, v):
var u_pos = get_point_position(u)
var v_pos = get_point_position(v)
return abs(u_pos.x - v_pos.x) + abs(u_pos.y - v_pos.y) + abs(u_pos.z - v_pos.z)
[/gdscript]
[csharp]
public partial class MyAStar : AStar3D
using Godot;
[GlobalClass]
public partial class MyAStar3D : AStar3D
{
public override float _ComputeCost(long fromId, long toId)
{
return Mathf.Abs((int)(fromId - toId));
Vector3 fromPoint = GetPointPosition(fromId);
Vector3 toPoint = GetPointPosition(toId);
return Mathf.Abs(fromPoint.X - toPoint.X) + Mathf.Abs(fromPoint.Y - toPoint.Y) + Mathf.Abs(fromPoint.Z - toPoint.Z);
}
public override float _EstimateCost(long fromId, long toId)
{
return Mathf.Min(0, Mathf.Abs((int)(fromId - toId)) - 1);
Vector3 fromPoint = GetPointPosition(fromId);
Vector3 toPoint = GetPointPosition(toId);
return Mathf.Abs(fromPoint.X - toPoint.X) + Mathf.Abs(fromPoint.Y - toPoint.Y) + Mathf.Abs(fromPoint.Z - toPoint.Z);
}
}
[/csharp]