Basic point graph. More...

Detailed Description

Basic point graph.

The point graph is the most basic graph structure, it consists of a number of interconnected points in space called nodes or waypoints.
The point graph takes a Transform object as "root", this Transform will be searched for child objects, every child object will be treated as a node. If recursive is enabled, it will also search the child objects of the children recursively. It will then check if any connections between the nodes can be made, first it will check if the distance between the nodes isn't too large (maxDistance) and then it will check if the axis aligned distance isn't too high. The axis aligned distance, named limits, is useful because usually an AI cannot climb very high, but linking nodes far away from each other, but on the same Y level should still be possible. limits and maxDistance are treated as being set to infinity if they are set to 0 (zero).
Lastly it will check if there are any obstructions between the nodes using raycasting which can optionally be thick.
One thing to think about when using raycasting is to either place the nodes a small distance above the ground in your scene or to make sure that the ground is not in the raycast mask to avoid the raycast from hitting the ground.

Alternatively, a tag can be used to search for nodes.

See Also: http://docs.unity3d.com/Manual/Tags.html

For larger graphs, it can take quite some time to scan the graph with the default settings. If you have the pro version you can enable 'optimizeForSparseGraph' which will in most cases reduce the calculation times drastically. If your graph is essentially only in the XZ plane (note, not XY), you can enable optimizeFor2D (called 'Optimize For XZ Plane' in the inspector).

Note: Does not support linecast because of obvious reasons.

Classes
struct	GetNearestHelper

Public Member Functions
PointNode	AddNode (Int3 position)
	Add a node to the graph at the specified position.

T	AddNode< T > (T node, Int3 position)
	Add a node with the specified type to the graph at the specified position.

GraphUpdateThreading	CanUpdateAsync (GraphUpdateObject o)

override int	CountNodes ()
	Count nodes in the graph.

override void	DeserializeExtraInfo (GraphSerializationContext ctx)
	Deserializes graph type specific node data.

override void	DeserializeSettingsCompatibility (GraphSerializationContext ctx)
	An old format for serializing settings.

override NNInfo	GetNearest (Vector3 position, NNConstraint constraint, GraphNode hint)
	Returns the nearest node to a position using the specified NNConstraint.

override NNInfo	GetNearestForce (Vector3 position, NNConstraint constraint)
	Returns the nearest node to a position using the specified constraint .

override void	GetNodes (GraphNodeDelegateCancelable del)
	Calls a delegate with all nodes in the graph.

virtual bool	IsValidConnection (GraphNode a, GraphNode b, out float dist)
	Returns if the connection between a and b is valid.

override void	PostDeserialization ()
	Called after all deserialization has been done for all graphs.

void	RebuildNodeLookup ()
	Rebuilds the lookup structure for nodes.

override void	RelocateNodes (Matrix4x4 oldMatrix, Matrix4x4 newMatrix)
	Relocates the nodes in this graph.

override void	ScanInternal (OnScanStatus statusCallback)
	Scans the graph, called from AstarPath.ScanLoop.

override void	SerializeExtraInfo (GraphSerializationContext ctx)
	Serializes graph type specific node data.

void	UpdateArea (GraphUpdateObject guo)
	Updates an area in the list graph.

void	UpdateAreaInit (GraphUpdateObject o)

Public Member Functions inherited from NavGraph
virtual void	Awake ()
	This will be called on the same time as Awake on the gameObject which the AstarPath script is attached to.

NNInfo	GetNearest (Vector3 position)
	Returns the nearest node to a position using the default NNConstraint.

NNInfo	GetNearest (Vector3 position, NNConstraint constraint)
	Returns the nearest node to a position using the specified NNConstraint.

virtual Color	NodeColor (GraphNode node, PathHandler data)

virtual void	OnDestroy ()
	Function for cleaning up references.

virtual void	OnDrawGizmos (bool drawNodes)
	Draw gizmos for the graph.

void	Scan ()

void	ScanGraph ()

void	ScanInternal ()
	Internal method for scanning graphs.

void	SetMatrix (Matrix4x4 m)
	Use to set both matrix and inverseMatrix at the same time.

Public Member Functions inherited from IUpdatableGraph
GraphUpdateThreading	CanUpdateAsync (GraphUpdateObject o)

void	UpdateArea (GraphUpdateObject o)
	Updates an area using the specified GraphUpdateObject.

void	UpdateAreaInit (GraphUpdateObject o)

Public Attributes
Vector3	limits
	Max distance along the axis for a connection to be valid.

LayerMask	mask
	Layer mask to use for raycast.

float	maxDistance
	Max distance for a connection to be valid.

PointNode[]	nodes
	All nodes in this graph.

bool	optimizeFor2D
	Optimizes for when the graph is mostly spread out in the XZ plane.

bool	optimizeForSparseGraph
	Optimizes the graph for sparse graphs.

bool	raycast = true
	Use raycasts to check connections.

bool	recursive = true
	Recursively search for child nodes to the root.

Transform	root
	Childs of this transform are treated as nodes.

string	searchTag
	If no root is set, all nodes with the tag is used as nodes.

bool	thickRaycast
	Use thick raycast.

float	thickRaycastRadius = 1
	Thick raycast radius.

bool	use2DPhysics
	Use the 2D Physics API.

Public Attributes inherited from NavGraph
AstarPath	active
	Reference to the AstarPath object in the scene.

bool	drawGizmos = true

uint	graphIndex
	Index of the graph, used for identification purposes.

Guid	guid
	Used as an ID of the graph, considered to be unique.

bool	infoScreenOpen
	Used in the editor to check if the info screen is open.

uint	initialPenalty
	Default penalty to apply to all nodes.

Matrix4x4	inverseMatrix = Matrix4x4.identity
	Inverse of matrix.

Matrix4x4	matrix = Matrix4x4.identity
	A matrix for translating/rotating/scaling the graph.

string	name
	Name of the graph.

bool	open
	Is the graph open in the editor.

Protected Member Functions
void	AddChildren (ref int c, Transform tr)
	Recursively adds childrens of a transform as nodes.

Static Protected Member Functions
static int	CountChildren (Transform tr)
	Recursively counds children of a transform.

Properties
int	nodeCount `[get, set]`
	Number of nodes in this graph.

Private Member Functions
void	AddToLookup (PointNode node)

Int3	WorldToLookupSpace (Int3 p)

Private Attributes
Int3	lookupCellSize

Int3	maxLookup

Int3	minLookup

Dictionary< Int3, PointNode >	nodeLookup

Static Private Attributes
static readonly Int3[]	ThreeDNeighbours

Additional Inherited Members
Static Public Member Functions inherited from NavGraph
static bool	InSearchTree (GraphNode node, Path path)
	Returns if the node is in the search tree of the path.

Package Functions inherited from NavGraph
virtual void	UnloadGizmoMeshes ()
	Called when temporary meshes used in OnDrawGizmos need to be unloaded to prevent memory leaks.

Member Function Documentation

void AddChildren	(	ref int	c,
		Transform	tr
	)

protected

Recursively adds childrens of a transform as nodes.

PointNode AddNode ( Int3 position )

Add a node to the graph at the specified position.

Note

Vector3 can be casted to Int3 using (Int3)myVector.

This needs to be called when it is safe to update nodes, which is

when scanning
during a graph update
inside a callback registered using AstarPath.RegisterSafeUpdate

T AddNode< T >	(	T	node,
		Int3	position
	)

Add a node with the specified type to the graph at the specified position.

Parameters

node	This must be a node created using T(AstarPath.active) right before the call to this method. The node parameter is only there because there is no new(AstarPath) constraint on generic type parameters.
position	The node will be set to this position.

Note

Vector3 can be casted to Int3 using (Int3)myVector.

This needs to be called when it is safe to update nodes, which is

when scanning
during a graph update
inside a callback registered using AstarPath.RegisterSafeUpdate

See Also: AstarPath.RegisterSafeUpdate

Type Constraints

T

:

PointNode

void AddToLookup ( PointNode node )

private

GraphUpdateThreading CanUpdateAsync ( GraphUpdateObject o )

static int CountChildren ( Transform tr )

staticprotected

Recursively counds children of a transform.

override int CountNodes ( )

virtual

Count nodes in the graph.

Note that this is, unless the graph type has overriden it, an O(n) operation.

Todo:: GridGraph should override this

Reimplemented from NavGraph.

override void DeserializeExtraInfo ( GraphSerializationContext ctx )

virtual

Deserializes graph type specific node data.

See Also: SerializeExtraInfo

Reimplemented from NavGraph.

override void DeserializeSettingsCompatibility ( GraphSerializationContext ctx )

virtual

An old format for serializing settings.

Deprecated:: This is deprecated now, but the deserialization code is kept to avoid loosing data when upgrading from older versions.

Reimplemented from NavGraph.

override NNInfo GetNearest	(	Vector3	position,
		NNConstraint	constraint,
		GraphNode	hint
	)

virtual

Returns the nearest node to a position using the specified NNConstraint.

Parameters

position	The position to try to find a close node to
hint	Can be passed to enable some graph generators to find the nearest node faster.
constraint	Can for example tell the function to try to return a walkable node. If you do not get a good node back, consider calling GetNearestForce.

Reimplemented from NavGraph.

override NNInfo GetNearestForce	(	Vector3	position,
		NNConstraint	constraint
	)

virtual

Returns the nearest node to a position using the specified constraint .

Returns: an NNInfo. This method will only return an empty NNInfo if there are no nodes which comply with the specified constraint.

Reimplemented from NavGraph.

override void GetNodes ( GraphNodeDelegateCancelable del )

virtual

Calls a delegate with all nodes in the graph.

This is the primary way of "looping" through all nodes in a graph.

This function should not change anything in the graph structure.

myGraph.GetNodes ((node) => {
    Debug.Log ("I found a node at position " + (Vector3)node.Position);
    return true;
});

Implements NavGraph.

virtual bool IsValidConnection	(	GraphNode	a,
		GraphNode	b,
		out float	dist
	)

virtual

Returns if the connection between a and b is valid.

Checks for obstructions using raycasts (if enabled) and checks for height differences.
As a bonus, it outputs the distance between the nodes too if the connection is valid

override void PostDeserialization ( )

virtual

Called after all deserialization has been done for all graphs.

Can be used to set up more graph data which is not serialized

Reimplemented from NavGraph.

void RebuildNodeLookup ( )

Rebuilds the lookup structure for nodes.

This is used when optimizeForSparseGraph is enabled.

You should call this method every time you move a node in the graph manually and you are using optimizeForSparseGraph, otherwise pathfinding might not work correctly.

A* Pro Feature:: This is an A* Pathfinding Project Pro feature only. This function/class/variable might not exist in the Free version of the A* Pathfinding Project or the functionality might be limited
The Pro version can be bought here

override void RelocateNodes	(	Matrix4x4	oldMatrix,
		Matrix4x4	newMatrix
	)

virtual

Relocates the nodes in this graph.

Assumes the nodes are already transformed using the "oldMatrix", then transforms them such that it will look like they have only been transformed using the "newMatrix". The "oldMatrix" is not required by all implementations of this function though (e.g the NavMesh generator).

The matrix the graph is transformed with is typically stored in the matrix field, so the typical usage for this method is

var myNewMatrix = Matrix4x4.TRS (...);

myGraph.RelocateNodes (myGraph.matrix, myNewMatrix);

So for example if you want to move all your nodes in e.g a point graph 10 units along the X axis from the initial position

var graph = AstarPath.astarData.pointGraph;
var m = Matrix4x4.TRS (new Vector3(10,0,0), Quaternion.identity, Vector3.one);
graph.RelocateNodes (graph.matrix, m);

Note: For grid graphs it is recommended to use the helper method RelocateNodes which takes parameters for center and nodeSize (and additional parameters) instead since it is both easier to use and is less likely to mess up pathfinding.

Warning: This method is lossy, so calling it many times may cause node positions to lose precision. For example if you set the scale to 0 in one call, and then to 1 in the next call, it will not be able to recover the correct positions since when the scale was 0, all nodes were scaled/moved to the same point. The same thing happens for other - less extreme - values as well, but to a lesser degree.

Version: Prior to version 3.6.1 the oldMatrix and newMatrix parameters were reversed by mistake.

Reimplemented from NavGraph.

override void ScanInternal ( OnScanStatus statusCallback )

virtual

Scans the graph, called from AstarPath.ScanLoop.

Override this function to implement custom scanning logic The statusCallback may be optionally called to show progress info in the editor

Implements NavGraph.

override void SerializeExtraInfo ( GraphSerializationContext ctx )

virtual

Serializes graph type specific node data.

This function can be overriden to serialize extra node information (or graph information for that matter) which cannot be serialized using the standard serialization. Serialize the data in any way you want and return a byte array. When loading, the exact same byte array will be passed to the DeserializeExtraInfo function.
These functions will only be called if node serialization is enabled.

Reimplemented from NavGraph.

void UpdateArea ( GraphUpdateObject guo )

Updates an area in the list graph.

Recalculates possibly affected connections, i.e all connectionlines passing trough the bounds of the guo will be recalculated

A* Pro Feature:: This is an A* Pathfinding Project Pro feature only. This function/class/variable might not exist in the Free version of the A* Pathfinding Project or the functionality might be limited
The Pro version can be bought here

void UpdateAreaInit ( GraphUpdateObject o )

Int3 WorldToLookupSpace ( Int3 p )

private

Member Data Documentation

Vector3 limits

Max distance along the axis for a connection to be valid.

0 = infinity

Int3 lookupCellSize

private

LayerMask mask

Layer mask to use for raycast.

float maxDistance

Max distance for a connection to be valid.

The value 0 (zero) will be read as infinity and thus all nodes not restricted by other constraints will be added as connections.

A negative value will disable any neighbours to be added. It will completely stop the connection processing to be done, so it can save you processing power if you don't these connections.

Int3 maxLookup

private

Int3 minLookup

private

Dictionary<Int3, PointNode> nodeLookup

private

PointNode [] nodes

All nodes in this graph.

Note that only the first nodeCount will be non-null.

You can also use the GetNodes method to get all nodes.

bool optimizeFor2D

Optimizes for when the graph is mostly spread out in the XZ plane.

Requires optimizeForSparseGraph.

When your graph is mostly spread out in the XZ plane instead of equally in all directions, you can tick this toggle to speed up some calculations. If you do not have a graph which is spread out mostly on the XZ plane, enabling this option will most likely degrade the performance of the graph instead of improve it.

A* Pro Feature:: This is an A* Pathfinding Project Pro feature only. This function/class/variable might not exist in the Free version of the A* Pathfinding Project or the functionality might be limited
The Pro version can be bought here

bool optimizeForSparseGraph

Optimizes the graph for sparse graphs.

This can reduce calculation times for both scanning and for normal path requests by huge amounts.

You should enable this when your maxDistance and/or limits variables are set relatively low compared to the world size. It reduces the number of node-node checks that need to be done during scan, and can also optimize getting the nearest node from the graph (such as when querying for a path).

Try enabling and disabling this option, check the scan times logged when you scan the graph to see if your graph is suited for this optimization or if it makes it slower.

The gain of using this optimization increases with larger graphs, the default scan algorithm is brute force and requires O(n^2) checks, this optimization along with a graph suited for it, requires only O(n) checks during scan.

Note: When you have this enabled, you will not be able to move nodes around using scripting unless you recalculate the lookup structure at the same time.

See Also: RebuildNodeLookup

A* Pro Feature:: This is an A* Pathfinding Project Pro feature only. This function/class/variable might not exist in the Free version of the A* Pathfinding Project or the functionality might be limited
The Pro version can be bought here

bool raycast = true

Use raycasts to check connections.

bool recursive = true

Recursively search for child nodes to the root.

Transform root

Childs of this transform are treated as nodes.

string searchTag

If no root is set, all nodes with the tag is used as nodes.

bool thickRaycast

Use thick raycast.

float thickRaycastRadius = 1

Thick raycast radius.

readonly Int3 [] ThreeDNeighbours

staticprivate

bool use2DPhysics

Use the 2D Physics API.

Property Documentation

int nodeCount

getset

Number of nodes in this graph.

The documentation for this class was generated from the following file:

/Users/arong/Unity/a-pathfinding-project/Assets/AstarPathfindingProject/Generators/PointGenerator.cs

Detailed Description

Classes

Public Member Functions

Public Attributes

Protected Member Functions

Static Protected Member Functions

Properties

Private Member Functions

Private Attributes

Static Private Attributes

Additional Inherited Members

Member Function Documentation

Member Data Documentation

Property Documentation