A* Pathfinding Project  4.3.2 The A* Pathfinding Project for Unity 3D
PointGraph Class Reference

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.

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.

Note
Does not support linecast because of obvious reasons.

## Public Types

enum  NodeDistanceMode { Node, Connection }
Distance query mode. More...

## Public Member Functions

Add a node to the graph at the specified position. More...

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

void ConnectNodes ()
Recalculates connections for all nodes in the graph. More...

override int CountNodes ()
Number of nodes in the graph. More...

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

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

override void GetNodes (System.Action< GraphNode > action)
Calls a delegate with all nodes in the graph. More...

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

void RebuildConnectionDistanceLookup ()
Rebuilds a cache used when nearestNodeDistanceMode = #NodeDistanceMode.ToConnection. More...

void RebuildNodeLookup ()
Rebuilds the lookup structure for nodes. More...

void RegisterConnectionLength (long sqrLength)
Ensures the graph knows that there is a connection with this length. More...

override void RelocateNodes (Matrix4x4 deltaMatrix)
Moves the nodes in this graph. More...

Public Member Functions inherited from NavGraph
NNInfoInternal GetNearest (Vector3 position)
Returns the nearest node to a position. More...

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

void GetNodes (System.Func< GraphNode, bool > action)
Calls a delegate with all nodes in the graph until the delegate returns false. More...

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

void RelocateNodes (Matrix4x4 oldMatrix, Matrix4x4 newMatrix)
Moves nodes in this graph. More...

void Scan ()
Scan the graph. More...

void ScanGraph ()
Scan the graph. More...

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

## Public Attributes

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

Layer mask to use for raycast. More...

float maxDistance
Max distance for a connection to be valid. More...

NodeDistanceMode nearestNodeDistanceMode
Distance query mode. More...

PointNode [] nodes
All nodes in this graph. More...

bool optimizeForSparseGraph
Optimizes the graph for sparse graphs. More...

bool raycast = true
Use raycasts to check connections. More...

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

Transform root
Childs of this transform are treated as nodes. More...

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

bool thickRaycast
Use thick raycast. More...

bool use2DPhysics
Use the 2D Physics API. More...

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

bool drawGizmos = true
Enable to draw gizmos in the Unity scene view. More...

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

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

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

uint initialPenalty
Default penalty to apply to all nodes. More...

Matrix4x4 inverseMatrix = Matrix4x4.identity
Inverse of matrix. More...

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

string name
Name of the graph. More...

bool open
Is the graph open in the editor. More...

## Protected Member Functions

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

virtual PointNode [] CreateNodes (int count)

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

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

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

override IEnumerable< ProgressScanInternal ()
Internal method to scan the graph. More...

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

Protected Member Functions inherited from NavGraph
virtual void DestroyAllNodes ()
Destroys all nodes in the graph. More...

void DrawUnwalkableNodes (float size)

virtual void OnDestroy ()
Function for cleaning up references. More...

## Static Protected Member Functions

static int CountChildren (Transform tr)
Recursively counds children of a transform. More...

## Properties

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

Properties inherited from NavGraph
bool exists` [get]`
True if the graph exists, false if it has been destroyed. More...

string IGraphInternals. SerializedEditorSettings` [get, set]`

Properties inherited from IGraphInternals
string SerializedEditorSettings` [get, set]`

## Private Member Functions

IEnumerable< ProgressConnectNodesAsync ()
Calculates connections for all nodes in the graph. More...

NNInfoInternal FindClosestConnectionPoint (PointNode node, Vector3 position)

NNInfoInternal GetNearestInternal (Vector3 position, NNConstraint constraint, bool fastCheck)

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

void IUpdatableGraph. UpdateAreaInit (GraphUpdateObject o)
May be called on the Unity thread before starting the update. More...

void IUpdatableGraph. UpdateAreaPost (GraphUpdateObject o)
May be called on the Unity thread after executing the update. More...

## Private Attributes

PointKDTree lookupTree = new PointKDTree()

long maximumConnectionLength = 0
Longest known connection. More...

## ◆ NodeDistanceMode

 enum NodeDistanceMode
strong

Distance query mode.

In the image above there are a few red nodes. Assume the agent is the orange circle. Using the Node mode the closest point on the graph that would be found would be the node at the bottom center which may not be what you want. Using the Connection mode it will find the closest point on the connection between the two nodes in the top half of the image.

When using the Connection option you may also want to use the Connection option for the Seeker's Start End Modifier snapping options. This is not strictly necessary, but it most cases it is what you want.

Pathfinding.StartEndModifier.exactEndPoint
Enumerator
Node

All nearest node queries find the closest node center.

This is the fastest option but it may not be what you want if you have long connections.

Connection

All nearest node queries find the closest point on edges between nodes.

This is useful if you have long connections where the agent might be closer to some unrelated node if it is standing on a long connection between two nodes. This mode is however slower than the Node mode.

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

## 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
var graph = AstarPath.active.data.pointGraph;
// Add 2 nodes and connect them
var node2 = graph.AddNode((Int3)(transform.position + Vector3.right));
var cost = (uint)(node2.position - node1.position).costMagnitude;
}));
Creating graphs during runtime

 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
Creating graphs during runtime
Type Constraints
 T : PointNode

 void AddToLookup ( PointNode node )
private

## ◆ CanUpdateAsync()

 GraphUpdateThreading IUpdatableGraph. CanUpdateAsync ( GraphUpdateObject o )
private

Implements IUpdatableGraph.

## ◆ ConnectNodes()

 void ConnectNodes ( )

Recalculates connections for all nodes in the graph.

This is useful if you have created nodes manually using AddNode and then want to connect them in the same way as the point graph normally connects nodes.

## ◆ ConnectNodesAsync()

 IEnumerable ConnectNodesAsync ( )
private

Calculates connections for all nodes in the graph.

This is an IEnumerable, you can iterate through it using e.g foreach to get progress information.

## ◆ CountChildren()

 static int CountChildren ( Transform tr )
staticprotected

Recursively counds children of a transform.

## ◆ CountNodes()

 override int CountNodes ( )
virtual

Number of nodes in the graph.

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

This is an O(1) operation for grid graphs and point graphs. For layered grid graphs it is an O(n) operation.

Reimplemented from NavGraph.

## ◆ CreateNodes()

 virtual PointNode [] CreateNodes ( int count )
protectedvirtual

## ◆ DeserializeExtraInfo()

 override void DeserializeExtraInfo ( GraphSerializationContext ctx )
protectedvirtual

Deserializes graph type specific node data.

SerializeExtraInfo

Reimplemented from NavGraph.

## ◆ DeserializeSettingsCompatibility()

 override void DeserializeSettingsCompatibility ( GraphSerializationContext ctx )
protectedvirtual

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.

## ◆ FindClosestConnectionPoint()

 NNInfoInternal FindClosestConnectionPoint ( PointNode node, Vector3 position )
private

## ◆ GetNearest()

 override NNInfoInternal 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.

## ◆ GetNearestForce()

 override NNInfoInternal 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.

## ◆ GetNearestInternal()

 NNInfoInternal GetNearestInternal ( Vector3 position, NNConstraint constraint, bool fastCheck )
private

## ◆ GetNodes()

 override void GetNodes ( System.Action< GraphNode > action )
virtual

Calls a delegate with all nodes in the graph.

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

Do not change the graph structure inside the delegate.

var gg = AstarPath.active.data.gridGraph;
gg.GetNodes(node => {
// Here is a node
Debug.Log("I found a node at position " + (Vector3)node.position);
});

If you want to store all nodes in a list you can do this

var gg = AstarPath.active.data.gridGraph;
List<GraphNode> nodes = new List<GraphNode>();
Pathfinding.AstarData.GetNodes

Implements NavGraph.

## ◆ IsValidConnection()

 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.

Note
This is not the same as checking if node a is connected to node b. That should be done using a.ContainsConnection(b)

## ◆ PostDeserialization()

 override void PostDeserialization ( GraphSerializationContext ctx )
protectedvirtual

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.

## ◆ RebuildConnectionDistanceLookup()

 void RebuildConnectionDistanceLookup ( )

Rebuilds a cache used when nearestNodeDistanceMode = #NodeDistanceMode.ToConnection.

## ◆ RebuildNodeLookup()

 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.

You may also call this after you have added many nodes using the AddNode method. When adding nodes using the AddNode method they will be added to the lookup structure. The lookup structure will rebalance itself when it gets too unbalanced however if you are sure you won't be adding any more nodes in the short term, you can make sure it is perfectly balanced and thus squeeze out the last bit of performance by calling this method. This can improve the performance of the GetNearest method slightly. The improvements are on the order of 10-20%.

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

## ◆ RegisterConnectionLength()

 void RegisterConnectionLength ( long sqrLength )

Ensures the graph knows that there is a connection with this length.

This is used when the nearest node distance mode is set to ToConnection. If you are modifying node connections yourself (i.e. manipulating the PointNode.connections array) then you must call this function when you add any connections.

When using PointNode.AddConnection this is done automatically. It is also done for all nodes when RebuildNodeLookup is called.

Parameters
 sqrLength The length of the connection in squared Int3 units. This can be calculated using (node1.position - node2.position).sqrMagnitudeLong.

## ◆ RelocateNodes()

 override void RelocateNodes ( Matrix4x4 deltaMatrix )
virtual

Moves the nodes in this graph.

Multiplies all node positions by deltaMatrix.

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.data.pointGraph;
var m = Matrix4x4.TRS (new Vector3(10,0,0), Quaternion.identity, Vector3.one);
graph.RelocateNodes (m);
Note
For grid graphs, navmesh graphs and recast graphs it is recommended to use their custom overloads of the RelocateNodes method which take parameters for e.g center and nodeSize (and additional parameters) instead since they are both easier to use and are less likely to mess up pathfinding.
Warning
This method is lossy for PointGraphs, so calling it many times may cause node positions to lose precision. For example if you set the scale to 0 in one call then all nodes will be scaled/moved to the same point and you will not be able to recover their original positions. The same thing happens for other - less extreme - values as well, but to a lesser degree.

Reimplemented from NavGraph.

## ◆ ScanInternal()

 override IEnumerable ScanInternal ( )
protectedvirtual

Internal method to scan the graph.

Called from AstarPath.ScanAsync. Override this function to implement custom scanning logic. Progress objects can be yielded to show progress info in the editor and to split up processing over several frames when using async scanning.

Implements NavGraph.

## ◆ SerializeExtraInfo()

 override void SerializeExtraInfo ( GraphSerializationContext ctx )
protectedvirtual

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.

## ◆ UpdateArea()

 void IUpdatableGraph. UpdateArea ( GraphUpdateObject guo )
private

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

Implements IUpdatableGraph.

## ◆ UpdateAreaInit()

 void IUpdatableGraph. UpdateAreaInit ( GraphUpdateObject o )
private

May be called on the Unity thread before starting the update.

CanUpdateAsync

Implements IUpdatableGraph.

## ◆ UpdateAreaPost()

 void IUpdatableGraph. UpdateAreaPost ( GraphUpdateObject o )
private

May be called on the Unity thread after executing the update.

CanUpdateAsync

Implements IUpdatableGraph.

## ◆ limits

 Vector3 limits

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

0 = infinity

## ◆ lookupTree

 PointKDTree lookupTree = new PointKDTree()
private

Layer mask to use for raycast.

## ◆ maxDistance

 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.

## ◆ maximumConnectionLength

 long maximumConnectionLength = 0
private

Longest known connection.

In squared Int3 units.

RegisterConnectionLength

## ◆ nearestNodeDistanceMode

 NodeDistanceMode nearestNodeDistanceMode

Distance query mode.

In the image above there are a few red nodes. Assume the agent is the orange circle. Using the Node mode the closest point on the graph that would be found would be the node at the bottom center which may not be what you want. Using the Connection mode it will find the closest point on the connection between the two nodes in the top half of the image.

When using the Connection option you may also want to use the Connection option for the Seeker's Start End Modifier snapping options. This is not strictly necessary, but it most cases it is what you want.

Pathfinding.StartEndModifier.exactEndPoint
NodeDistanceMode

If you enable this during runtime, you will need to call RebuildConnectionDistanceLookup to make sure some cache data is properly recalculated. If the graph doesn't have any nodes yet or if you are going to scan the graph afterwards then you do not need to do this.

## ◆ nodes

 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.

## ◆ optimizeForSparseGraph

 bool optimizeForSparseGraph

Optimizes the graph for sparse graphs.

This can reduce calculation times for both scanning and for normal path requests by huge amounts. 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 (assuming the connection distance limits are reasonable).

Warning
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.
RebuildNodeLookup

If you enable this during runtime, you will need to call RebuildNodeLookup to make sure any existing nodes are added to the lookup structure. If the graph doesn't have any nodes yet or if you are going to scan the graph afterwards then you do not need to do this.

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

## ◆ raycast

 bool raycast = true

Use raycasts to check connections.

## ◆ recursive

 bool recursive = true

Recursively search for child nodes to the root.

## ◆ root

 Transform root

Childs of this transform are treated as nodes.

## ◆ searchTag

 string searchTag

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

## ◆ thickRaycast

 bool thickRaycast

Use thick raycast.

## ◆ use2DPhysics

 bool use2DPhysics

Use the 2D Physics API.

## ◆ nodeCount

 int nodeCount
getprotected set

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