com.badlogic.gdx.ai.pfa

Class PathSmoother<N,V extends com.badlogic.gdx.math.Vector<V>>

java.lang.Object

com.badlogic.gdx.ai.pfa.PathSmoother<N,V>

Type Parameters:

N - Type of node

V - Type of vector, either 2D or 3D, implementing the Vector interface

public class PathSmoother<N,V extends com.badlogic.gdx.math.Vector<V>>
extends java.lang.Object

A PathSmoother takes a SmoothableGraphPath and transforms it by linking directly the nodes that are in line of sight. The smoothed path contains at most as many nodes as the original path. Also, the nodes in the smoothed path are unlikely to have any connections between them (if they were connected in the graph, the pathfinder would have found the smoothed route directly, unless their connections had dramatically large costs).

Some world representations are more prone to rough paths than others. Fore example, tile-based graphs tend to be highly erratic. The final appearance also depends on how characters act on the path. If they are using some kind of path following steering behavior, then the path will be gently smoothed by the steering. It is worth testing your game before assuming the path will need smoothing.

For some games, path smoothing is essential to get the AI looking smart. The path smoothing algorithm is rather simple but involves raycast and can be somewhat time-consuming.

The algorithm assumes that there is a clear route between any two adjacent nodes in the given path. Although this algorithm produces a smooth path, it doesn't search all possible smoothed paths to find the best one, but the final result is usually much more satisfactory than the original path.

Constructor Summary

Constructors

Constructor and Description
PathSmoother(RaycastCollisionDetector<V> raycastCollisionDetector) Creates a PathSmoother using the given RaycastCollisionDetector

Method Summary

Modifier and Type	Method and Description
boolean	smoothPath(PathSmootherRequest<N,V> request, long timeToRun) Smoothes in place the path specified by the given request, possibly over multiple consecutive frames.
int	smoothPath(SmoothableGraphPath<N,V> path) Smoothes the given path in place.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

PathSmoother

public PathSmoother(RaycastCollisionDetector<V> raycastCollisionDetector)

Creates a PathSmoother using the given RaycastCollisionDetector

Parameters:

raycastCollisionDetector - the raycast collision detector

Method Detail

smoothPath

public int smoothPath(SmoothableGraphPath<N,V> path)

Smoothes the given path in place.

Parameters:

path - the path to smooth

Returns:

the number of nodes removed from the path.

smoothPath

public boolean smoothPath(PathSmootherRequest<N,V> request,
                          long timeToRun)

Smoothes in place the path specified by the given request, possibly over multiple consecutive frames.

Parameters:

request - the path smoothing request

timeToRun - the time in nanoseconds that this call can use on the current frame

Returns:

true if this operation has completed; false if more time is needed to complete.