Class PathUtilities

List<GraphNode> BFS (

GraphNode	seed	The node to start the search from.
int	depth	The maximum node-distance from the seed node.
int	tagMask=-1	Optional mask for tags. This is a bitmask.
System.Func<GraphNode, bool>	filter=null	Optional filter for which nodes to search. You can combine this with depth = int.MaxValue and tagMask = -1 to make the filter determine everything. Only walkable nodes are searched regardless of the filter. If the filter function returns false the node will be treated as unwalkable.

)

Returns all nodes up to a given node-distance from the seed node.

This function performs a BFS (breadth-first search) or flood fill of the graph and returns all nodes within a specified node distance which can be reached from the seed node. In almost all cases when depth is large enough this will be identical to returning all nodes which have the same area as the seed node. In the editor areas are displayed as different colors of the nodes. The only case where it will not be so is when there is a one way path from some part of the area to the seed node but no path from the seed node to that part of the graph.

The returned list is sorted by node distance from the seed node i.e distance is measured in the number of nodes the shortest path from seed to that node would pass through. Note that the distance measurement does not take heuristics, penalties or tag penalties.

Depending on the number of nodes, this function can take quite some time to calculate so don't use it too often or it might affect the framerate of your game.

The video below shows the BFS result with varying values of depth. Points are sampled on the nodes using GetPointsOnNodes.

void FormationPacked (

List<Vector3>	currentPositions
Vector3	destination
float	clearanceRadius

)

void GetPointsAroundPoint (

Vector3	center	The point to generate points around
IRaycastableGraph	g	The graph to use for linecasting. If you are only using one graph, you can get this by AstarPath.active.graphs[0] as IRaycastableGraph. Note that not all graphs are raycastable, recast, navmesh and grid graphs are raycastable. On recast and navmesh it works the best.
List<Vector3>	previousPoints	The points to use for reference. Note that these should not be in world space. They are treated as relative to center. The new points will overwrite the existing points in the list. The result will be in world space, not relative to center.
float	radius	The final points will be at most this distance from center.
float	clearanceRadius	The points will if possible be at least this distance from each other.

)

Will calculate a number of points around center which are on the graph and are separated by clearance from each other.

The maximum distance from center to any point will be radius. Points will first be tried to be laid out as previousPoints and if that fails, random points will be selected. This is great if you want to pick a number of target points for group movement. If you pass all current agent points from e.g the group's average position this method will return target points so that the units move very little within the group, this is often aesthetically pleasing and reduces jitter if using some kind of local avoidance.

void GetPointsAroundPointWorld (

Vector3	p	The point to generate points around
IRaycastableGraph	g	The graph to use for linecasting. If you are only using one graph, you can get this by AstarPath.active.graphs[0] as IRaycastableGraph. Note that not all graphs are raycastable, recast, navmesh and grid graphs are raycastable. On recast and navmesh it works the best.
List<Vector3>	previousPoints	The points to use for reference. Note that these are in world space. The new points will overwrite the existing points in the list. The result will be in world space.
float	radius	The final points will be at most this distance from p.
float	clearanceRadius	The points will if possible be at least this distance from each other.

)

Will calculate a number of points around p which are on the graph and are separated by clearance from each other.

This is like GetPointsAroundPoint except that previousPoints are treated as being in world space. The average of the points will be found and then that will be treated as the group center.

void GetPointsAroundPointWorldFlexible (

Vector3	center
Quaternion	rotation
List<Vector3>	positions

)

List<Vector3> GetPointsOnNodes (

List<GraphNode>	nodes
int	count
float	clearanceRadius=0

)

Returns randomly selected points on the specified nodes with each point being separated by clearanceRadius from each other.

Selecting points ON the nodes only works for TriangleMeshNode (used by Recast Graph and Navmesh Graph) and GridNode (used by GridGraph). For other node types, only the positions of the nodes will be used.

clearanceRadius will be reduced if no valid points can be found.

List<GraphNode> GetReachableNodes (

GraphNode	seed	The node to start the search from.
int	tagMask=-1	Optional mask for tags. This is a bitmask.
System.Func<GraphNode, bool>	filter=null	Optional filter for which nodes to search. You can combine this with tagMask = -1 to make the filter determine everything. Only walkable nodes are searched regardless of the filter. If the filter function returns false the node will be treated as unwalkable.

)

Returns all nodes reachable from the seed node.

This function performs a DFS (depth-first-search) or flood fill of the graph and returns all nodes which can be reached from the seed node. In almost all cases this will be identical to returning all nodes which have the same area as the seed node. In the editor areas are displayed as different colors of the nodes. The only case where it will not be so is when there is a one way path from some part of the area to the seed node but no path from the seed node to that part of the graph.

The returned list is not sorted in any particular way.

Depending on the number of reachable nodes, this function can take quite some time to calculate so don't use it too often or it might affect the framerate of your game.

List<Vector3> GetSpiralPoints (

int	count
float	clearance

)

Returns points in a spiral centered around the origin with a minimum clearance from other points.

The points are laid out on the involute of a circle

bool IsPathPossible (

GraphNode	node1
GraphNode	node2

)

Returns if there is a walkable path from node1 to node2.

This method is extremely fast because it only uses precalculated information.

GraphNode node1 = AstarPath.active.GetNearest(point1, NNConstraint.Default).node;
GraphNode node2 = AstarPath.active.GetNearest(point2, NNConstraint.Default).node;

if (PathUtilities.IsPathPossible(node1, node2)) {
// Yay, there is a path between those two nodes
}


bool IsPathPossible (

List<GraphNode>

nodes

)

Returns if there are walkable paths between all nodes in the list.

Returns true for empty lists.

bool IsPathPossible (

List<GraphNode>	nodes
int	tagMask

)

Returns if there are walkable paths between all nodes in the list.

This method will actually only check if the first node can reach all other nodes. However this is equivalent in 99% of the cases since almost always the graph connections are bidirectional. If you are not aware of any cases where you explicitly create unidirectional connections this method can be used without worries.

Returns true for empty lists

Dictionary<GraphNode, int> BFSMap

Queue<GraphNode> BFSQueue

Vector3 InvoluteOfCircle (

float	a
float	t

)

Returns the XZ coordinate of the involute of circle.