GridGraph Class Reference

Generates a grid of nodes. More...

Detailed Description

Generates a grid of nodes.

The GridGraph does exactly what the name implies, generates nodes in a grid pattern.
Grid graphs suit well to when you already have a grid based world. Features:

• You can update the graph during runtime (good for e.g Tower Defence or RTS games)
• Throw any scene at it, with minimal configurations you can get a good graph from it.
• Supports raycast and the funnel algorithm
• Predictable pattern
• Can apply penalty and walkability values from a supplied image
• Perfect for terrain worlds since it can make areas unwalkable depending on the slope

The The Snap Size button snaps the internal size of the graph to exactly contain the current number of nodes, i.e not contain 100.3 nodes but exactly 100 nodes.
This will make the "center" coordinate more accurate.
Updating the graph during runtime Any graph which implements the IUpdatableGraph interface can be updated during runtime.
For grid graphs this is a great feature since you can update only a small part of the grid without causing any lag like a complete rescan would.
If you for example just have instantiated a sphere obstacle in the scene and you want to update the grid where that sphere was instantiated, you can do this:

AstarPath.active.UpdateGraphs (ob.collider.bounds); 

Where ob is the obstacle you just instantiated (a GameObject).
As you can see, the UpdateGraphs function takes a Bounds parameter and it will send an update call to all updateable graphs.
A grid graph will update that area and a small margin around it equal to collision testing diameter/2

See also

Graph Updates during Runtime for more info about updating Graph Types during runtime

Hexagon graphs The graph can be configured to work like a hexagon graph with some simple settings. Just set the neighbours (called 'connections' in the editor) field to 'Six' and then click the 'Configure as Hexagon Graph' button that will show up. That will set the isometricAngle field to 54.74 (more precisely 90-atan(1/sqrt(2))) and enable uniformEdgeCosts.

Then the graph will work like a hexagon graph. You might want to rotate it to better match your game however.

Note however that the snapping to the closest node is not exactly as you would expect in a real hexagon graph, but it is close enough that you will likely not notice.

Configure using code

// This holds all graph data
AstarData data = AstarPath.active.data;

// This creates a Grid Graph
GridGraph gg = data.AddGraph(typeof(GridGraph)) as GridGraph;

// Setup a grid graph with some values
int width = 50;
int depth = 50;
float nodeSize = 1;
gg.center = new Vector3 (10,0,0);

// Updates internal size from the above values
gg.SetDimensions(width, depth, nodeSize);

// Scans all graphs, do not call gg.Scan(), that is an internal method
AstarPath.active.Scan();

Tree colliders It seems that Unity will only generate tree colliders at runtime when the game is started. For this reason, the grid graph will not pick up tree colliders when outside of play mode but it will pick them up once the game starts. If it still does not pick them up make sure that the trees actually have colliders attached to them and that the tree prefabs are in the correct layer (the layer should be included in the 'Collision Testing' mask).

See also

Pathfinding.GraphCollision for documentation on the 'Height Testing' and 'Collision Testing' sections of the grid graph settings.

Classes
class	TextureData
	Used for using a texture as a source for a grid graph. More...

Public Member Functions
	GridGraph ()
virtual void	CalculateConnections (GridNodeBase node)
	Calculates the grid connections for a single node. More...
virtual void	CalculateConnections (GridNode[] nodes, int x, int z, GridNode node)
	Calculates the grid connections for a single node. More...
virtual void	CalculateConnections (int x, int z, GridNode node)
	Calculates the grid connections for a single node. More...
virtual void	CalculateConnections (int x, int z)
	Calculates the grid connections for a single node. More...
GraphTransform	CalculateTransform ()
	Returns a new transform which transforms graph space to world space. More...
bool	CheckConnection (GridNode node, int dir)
	Returns if node is connected to it's neighbour in the specified direction. More...
override int	CountNodes ()
	Number of nodes in the graph. More...
virtual void	ErodeWalkableArea ()
	Erodes the walkable area. More...
void	ErodeWalkableArea (int xmin, int zmin, int xmax, int zmax)
	Erodes the walkable area. More...
void	GenerateMatrix ()
	Generates the matrix used for translating nodes from grid coordinates to world coordinates. More...
uint	GetConnectionCost (int dir)
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...
GridNode	GetNodeConnection (GridNode node, int dir)
override void	GetNodes (System.Action< GraphNode > action)
	Calls a delegate with all nodes in the graph. More...
List< GraphNode >	GetNodesInArea (Bounds bounds)
List< GraphNode >	GetNodesInArea (GraphUpdateShape shape)
List< GraphNode >	GetNodesInArea (Bounds bounds, GraphUpdateShape shape)
List< GraphNode >	GetNodesInRegion (Bounds bounds)
	All nodes inside the bounding box. More...
List< GraphNode >	GetNodesInRegion (GraphUpdateShape shape)
	All nodes inside the shape. More...
virtual List< GraphNode >	GetNodesInRegion (IntRect rect)
	Get all nodes in a rectangle. More...
virtual int	GetNodesInRegion (IntRect rect, GridNodeBase[] buffer)
	Get all nodes in a rectangle. More...
Int3	GraphPointToWorld (int x, int z, float height)
	Transform a point in graph space to world space. More...
bool	HasNodeConnection (GridNode node, int dir)
bool	HasNodeConnection (int index, int x, int z, int dir)
virtual bool	IsValidConnection (GridNodeBase node1, GridNodeBase node2)
	Returns true if a connection between the adjacent nodes n1 and n2 is valid. More...
bool	Linecast (Vector3 from, Vector3 to)
	Returns if there is an obstacle between from and to on the graph. More...
bool	Linecast (Vector3 from, Vector3 to, GraphNode hint)
	Returns if there is an obstacle between from and to on the graph. More...
bool	Linecast (Vector3 from, Vector3 to, GraphNode hint, out GraphHitInfo hit)
	Returns if there is an obstacle between from and to on the graph. More...
bool	Linecast (Vector3 from, Vector3 to, GraphNode hint, out GraphHitInfo hit, List< GraphNode > trace)
	Returns if there is an obstacle between from and to on the graph. More...
override void	OnDrawGizmos (RetainedGizmos gizmos, bool drawNodes)
	Draw gizmos for the graph. More...
virtual void	RecalculateCell (int x, int z, bool resetPenalties=true, bool resetTags=true)
	Recalculates single node in the graph. More...
override void	RelocateNodes (Matrix4x4 deltaMatrix)
	Moves the nodes in this graph. More...
void	RelocateNodes (Vector3 center, Quaternion rotation, float nodeSize, float aspectRatio=1, float isometricAngle=0)
	Relocate the grid graph using new settings. More...
void	SetDimensions (int width, int depth, float nodeSize)
	Updates unclampedSize from width, depth and nodeSize values. More...
void	SetNodeConnection (GridNode node, int dir, bool value)
void	SetNodeConnection (int index, int x, int z, int dir, bool value)
	Set if connection in the specified direction should be enabled. More...
virtual void	SetUpOffsetsAndCosts ()
	Sets up neighbourOffsets with the current settings. More...
bool	SnappedLinecast (Vector3 from, Vector3 to, GraphNode hint, out GraphHitInfo hit)
	Returns if there is an obstacle between from and to on the graph. More...
virtual void	UpdateNodePositionCollision (GridNode node, int x, int z, bool resetPenalty=true)
	Updates position, walkability and penalty for the node. More...
void	UpdateSizeFromWidthDepth ()
	Updates unclampedSize from width, depth and nodeSize values. More...
void	UpdateTransform ()
	Updates the transform field which transforms graph space to world space. More...
Public Member Functions inherited from NavGraph
NNInfoInternal	GetNearest (Vector3 position)
	Returns the nearest node to a position using the default NNConstraint. 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...
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...

Static Public Member Functions
static void	CalculateConnections (GridNode node)
	Calculates the grid connections for a single node. More...

Public Attributes
const int	getNearestForceOverlap = 2
	In GetNearestForce, determines how far to search after a valid node has been found. More...
readonly uint []	neighbourCosts = new uint[8]
	Costs to neighbour nodes. More...
readonly int []	neighbourOffsets = new int[8]
	Index offset to get neighbour nodes. More...
readonly int []	neighbourXOffsets = new int[8]
	Offsets in the X direction for neighbour nodes. More...
readonly int []	neighbourZOffsets = new int[8]
	Offsets in the Z direction for neighbour nodes. More...
GridNode []	nodes
	All nodes in this graph. 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	CalculateAffectedRegions (GraphUpdateObject o, out IntRect originalRect, out IntRect affectRect, out IntRect physicsRect, out bool willChangeWalkability, out int erosion)
bool	ClipLineSegmentToBounds (Vector3 a, Vector3 b, out Vector3 outA, out Vector3 outB)
	Clips a line segment in graph space to the graph bounds. More...
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	DestroyAllNodes ()
	Destroys all nodes in the graph. More...
virtual bool	ErosionAnyFalseConnections (GraphNode baseNode)
	True if the node has any blocked connections. More...
virtual List< GraphNode >	GetNodesInRegion (Bounds bounds, GraphUpdateShape shape)
	All nodes inside the shape or if null, the bounding box. More...
IntRect	GetRectFromBounds (Bounds bounds)
	A rect with all nodes that the bounds could touch. More...
override void	OnDestroy ()
	This function will be called when this graph is destroyed. More...
override void	PostDeserialization (GraphSerializationContext ctx)
	Called after all deserialization has been done for all graphs. More...
override IEnumerable< Progress >	ScanInternal ()
	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
void	DrawUnwalkableNodes (float size)

Static Protected Member Functions
static float	CrossMagnitude (Vector2 a, Vector2 b)
	Magnitude of the cross product a x b. More...

Static Package Attributes
static readonly int []	hexagonNeighbourIndices = { 0, 1, 5, 2, 3, 7 }
	Which neighbours are going to be used when neighbours=6. More...

Properties
int	Depth [get, set]
virtual int	LayerCount [get]
	Number of layers in the graph. More...
Vector2	size [get, protected set]
	Size of the grid. More...
GraphTransform	transform [get, private set]
	Determines how the graph transforms graph space to world space. More...
virtual bool	uniformWidthDepthGrid [get]
	This is placed here so generators inheriting from this one can override it and set it to false. More...
int	Width [get, set]
Properties inherited from NavGraph
bool	exists [get]
	True if the graph exists, false if it has been destroyed. More...
Properties inherited from ITransformedGraph
GraphTransform	transform [get]

Private Member Functions
void	CalculateDimensions (out int width, out int depth, out float nodeSize)
	Calculates the width/depth of the graph from unclampedSize and nodeSize. More...
GraphUpdateThreading IUpdatableGraph.	CanUpdateAsync (GraphUpdateObject o)
void	CreateNavmeshSurfaceVisualization (GridNodeBase[] nodes, int nodeCount, GraphGizmoHelper helper)
	Draw the surface as well as an outline of the grid graph. More...
void	ErodeNode (GraphNode node)
	Internal method used for erosion. More...
void	ErodeNodeWithTags (GraphNode node, int iteration)
	Internal method used for erosion. More...
void	ErodeNodeWithTagsInit (GraphNode node)
	Internal method used for erosion. More...
GridNode	GetNodeConnection (int index, int x, int z, int dir)
	Get the connecting node from the node at (x,z) in the specified direction. More...
void	RemoveGridGraphFromStatic ()
void IUpdatableGraph.	UpdateArea (GraphUpdateObject o)
	Internal function to update an area of the 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...

Inspector - Settings
bool	useRaycastNormal [get]
	Use heigh raycasting normal for max slope calculation. More...
int	width
	Width of the grid in nodes. More...
int	depth
	Depth (height) of the grid in nodes. More...
float	aspectRatio = 1F
	Scaling of the graph along the X axis. More...
float	isometricAngle
	Angle to use for the isometric projection. More...
bool	uniformEdgeCosts
	If true, all edge costs will be set to the same value. More...
Vector3	rotation
	Rotation of the grid in degrees. More...
Vector3	center
	Center point of the grid. More...
Vector2	unclampedSize
	Size of the grid. More...
float	nodeSize = 1
	Size of one node in world units. More...
GraphCollision	collision
	Settings on how to check for walkability and height. More...
float	maxClimb = 0.4F
	The max position difference between two nodes to enable a connection. More...
float	maxSlope = 90
	The max slope in degrees for a node to be walkable. More...
int	erodeIterations
	Erosion of the graph. More...
bool	erosionUseTags
	Use tags instead of walkability for erosion. More...
int	erosionFirstTag = 1
	Tag to start from when using tags for erosion. More...
NumNeighbours	neighbours = NumNeighbours.Eight
	Number of neighbours for each node. More...
bool	cutCorners = true
	If disabled, will not cut corners on obstacles. More...
float	penaltyPositionOffset
	Offset for the position when calculating penalty. More...
bool	penaltyPosition
	Use position (y-coordinate) to calculate penalty. More...
float	penaltyPositionFactor = 1F
	Scale factor for penalty when calculating from position. More...
bool	penaltyAngle
float	penaltyAngleFactor = 100F
	How much penalty is applied depending on the slope of the terrain. More...
float	penaltyAnglePower = 1
	How much extra to penalize very steep angles. More...
bool	useJumpPointSearch
bool	showMeshOutline = true
	Show an outline of the grid nodes in the Unity Editor. More...
bool	showNodeConnections
	Show the connections between the grid nodes in the Unity Editor. More...
bool	showMeshSurface = true
	Show the surface of the graph. More...
TextureData	textureData = new TextureData()
	Holds settings for using a texture as source for a grid graph. More...

Constructor & Destructor Documentation

GridGraph()

GridGraph

(

)

Member Function Documentation

CalculateAffectedRegions()

void CalculateAffectedRegions ( GraphUpdateObject  o, out IntRect  originalRect, out IntRect  affectRect, out IntRect  physicsRect, out bool  willChangeWalkability, out int  erosion  )

protected

CalculateConnections() [1/5]

static void CalculateConnections ( GridNode  node )

static

Calculates the grid connections for a single node.

Deprecated:

Use the instance function instead

CalculateConnections() [2/5]

virtual void CalculateConnections ( GridNodeBase  node )

virtual

Calculates the grid connections for a single node.

Convenience function, it's slightly faster to use CalculateConnections(int,int) but that will only show when calculating for a large number of nodes. This function will also work for both grid graphs and layered grid graphs.

Reimplemented in LayerGridGraph.

CalculateConnections() [3/5]

virtual void CalculateConnections ( GridNode []  nodes, int  x, int  z, GridNode  node  )

virtual

Calculates the grid connections for a single node.

Deprecated:

CalculateConnections no longer takes a node array, it just uses the one on the graph

CalculateConnections() [4/5]

virtual void CalculateConnections ( int  x, int  z, GridNode  node  )

virtual

Calculates the grid connections for a single node.

Deprecated:

Use CalculateConnections(x,z) or CalculateConnections(node) instead

CalculateConnections() [5/5]

virtual void CalculateConnections ( int  x, int  z  )

virtual

Calculates the grid connections for a single node.

Note that to ensure that connections are completely up to date after updating a node you have to calculate the connections for both the changed node and its neighbours.

In a layered grid graph, this will recalculate the connections for all nodes in the (x,z) cell (it may have multiple layers of nodes).

See also

CalculateConnections(GridNodeBase)

Reimplemented in LayerGridGraph.

CalculateDimensions()

void CalculateDimensions ( out int  width, out int  depth, out float  nodeSize  )

private

Calculates the width/depth of the graph from unclampedSize and nodeSize.

The node size may be changed due to constraints that the width/depth is not allowed to be larger than 1024 (artificial limit).

CalculateTransform()

GraphTransform CalculateTransform

(

)

Returns a new transform which transforms graph space to world space.

Does not update the transform field.

See also

UpdateTransform

CanUpdateAsync()

GraphUpdateThreading IUpdatableGraph. CanUpdateAsync ( GraphUpdateObject  o )

private

Implements IUpdatableGraph.

CheckConnection()

bool CheckConnection	(	GridNode	node,
		int	dir
	)

Returns if node is connected to it's neighbour in the specified direction.

This will also return true if neighbours = NumNeighbours.Four, the direction is diagonal and one can move through one of the adjacent nodes to the targeted node.

See also

neighbourOffsets

ClipLineSegmentToBounds()

bool ClipLineSegmentToBounds ( Vector3  a, Vector3  b, out Vector3  outA, out Vector3  outB  )

protected

Clips a line segment in graph space to the graph bounds.

That is (0,0,0) is the bottom left corner of the graph and (width,0,depth) is the top right corner. The first node is placed at (0.5,y,0.5). One unit distance is the same as nodeSize.

Returns false if the line segment does not intersect the graph at all.

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.

Reimplemented in LayerGridGraph.

CreateNavmeshSurfaceVisualization()

void CreateNavmeshSurfaceVisualization ( GridNodeBase []  nodes, int  nodeCount, GraphGizmoHelper  helper  )

private

Draw the surface as well as an outline of the grid graph.

The nodes will be drawn as squares (or hexagons when using neighbours = Six).

CrossMagnitude()

static float CrossMagnitude ( Vector2  a, Vector2  b  )

staticprotected

Magnitude of the cross product a x b.

DeserializeExtraInfo()

override void DeserializeExtraInfo ( GraphSerializationContext  ctx )

protectedvirtual

Deserializes graph type specific node data.

See also

SerializeExtraInfo

Reimplemented from NavGraph.

Reimplemented in LayerGridGraph.

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.

DestroyAllNodes()

override void DestroyAllNodes ( )

protectedvirtual

Destroys all nodes in the graph.

Warning

This is an internal method. Unless you have a very good reason, you should probably not call it.

Reimplemented from NavGraph.

ErodeNode()

void ErodeNode ( GraphNode  node )

private

Internal method used for erosion.

ErodeNodeWithTags()

void ErodeNodeWithTags ( GraphNode  node, int  iteration  )

private

Internal method used for erosion.

ErodeNodeWithTagsInit()

void ErodeNodeWithTagsInit ( GraphNode  node )

private

Internal method used for erosion.

ErodeWalkableArea() [1/2]

virtual void ErodeWalkableArea ( )

virtual

Erodes the walkable area.

See also

erodeIterations

ErodeWalkableArea() [2/2]

void ErodeWalkableArea	(	int	xmin,
		int	zmin,
		int	xmax,
		int	zmax
	)

Erodes the walkable area.

xmin, zmin (inclusive)
xmax, zmax (exclusive)

See also

erodeIterations

ErosionAnyFalseConnections()

virtual bool ErosionAnyFalseConnections ( GraphNode  baseNode )

protectedvirtual

True if the node has any blocked connections.

For 4 and 8 neighbours the 4 axis aligned connections will be checked. For 6 neighbours all 6 neighbours will be checked.

Internal method used for erosion.

Reimplemented in LayerGridGraph.

GenerateMatrix()

void GenerateMatrix

(

)

Generates the matrix used for translating nodes from grid coordinates to world coordinates.

Deprecated:

This method has been renamed to UpdateTransform

GetConnectionCost()

uint GetConnectionCost

(

int

dir

)

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.

Reimplemented in LayerGridGraph.

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.

Reimplemented in LayerGridGraph.

GetNodeConnection() [1/2]

GridNode GetNodeConnection	(	GridNode	node,
		int	dir
	)

GetNodeConnection() [2/2]

GridNode GetNodeConnection ( int  index, int  x, int  z, int  dir  )

private

Get the connecting node from the node at (x,z) in the specified direction.

Returns

A GridNode if the node has a connection to that node. Null if no connection in that direction exists

See also

GridNode

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>();
        gg.GetNodes((System.Action<GraphNode>)nodes.Add);

Implements NavGraph.

Reimplemented in LayerGridGraph.

GetNodesInArea() [1/3]

List<GraphNode> GetNodesInArea

(

Bounds

bounds

)

Deprecated:

This method has been renamed to GetNodesInRegion

GetNodesInArea() [2/3]

List<GraphNode> GetNodesInArea

(

GraphUpdateShape

shape

)

Deprecated:

This method has been renamed to GetNodesInRegion

GetNodesInArea() [3/3]

List<GraphNode> GetNodesInArea	(	Bounds	bounds,
		GraphUpdateShape	shape
	)

Deprecated:

This method has been renamed to GetNodesInRegion

GetNodesInRegion() [1/5]

List<GraphNode> GetNodesInRegion

(

Bounds

bounds

)

All nodes inside the bounding box.

Note

Be nice to the garbage collector and pool the list when you are done with it (optional)

See also

Pathfinding.Util.ListPool

GetNodesInRegion(GraphUpdateShape)

GetNodesInRegion() [2/5]

List<GraphNode> GetNodesInRegion

(

GraphUpdateShape

shape

)

All nodes inside the shape.

Note

Be nice to the garbage collector and pool the list when you are done with it (optional)

See also

Pathfinding.Util.ListPool

GetNodesInRegion(Bounds)

GetNodesInRegion() [3/5]

virtual List<GraphNode> GetNodesInRegion ( Bounds  bounds, GraphUpdateShape  shape  )

protectedvirtual

All nodes inside the shape or if null, the bounding box.

If a shape is supplied, it is assumed to be contained inside the bounding box.

See also

GraphUpdateShape.GetBounds

Reimplemented in LayerGridGraph.

GetNodesInRegion() [4/5]

virtual List<GraphNode> GetNodesInRegion ( IntRect  rect )

virtual

Get all nodes in a rectangle.

Parameters

rect	Region in which to return nodes. It will be clamped to the grid.

Reimplemented in LayerGridGraph.

GetNodesInRegion() [5/5]

virtual int GetNodesInRegion ( IntRect  rect, GridNodeBase []  buffer  )

virtual

Get all nodes in a rectangle.

Parameters

rect	Region in which to return nodes. It will be clamped to the grid.
buffer	Buffer in which the nodes will be stored. Should be at least as large as the number of nodes that can exist in that region.

Returns

The number of nodes written to the buffer.

Note

This method is much faster than GetNodesInRegion(IntRect) which returns a list because this method can make use of the highly optimized System.Array.Copy method.

Reimplemented in LayerGridGraph.

GetRectFromBounds()

IntRect GetRectFromBounds ( Bounds  bounds )

protected

A rect with all nodes that the bounds could touch.

This correctly handles rotated graphs and other transformations. The returned rect is guaranteed to not extend outside the graph bounds.

GraphPointToWorld()

Int3 GraphPointToWorld	(	int	x,
		int	z,
		float	height
	)

Transform a point in graph space to world space.

This will give you the node position for the node at the given x and z coordinate if it is at the specified height above the base of the graph.

HasNodeConnection() [1/2]

bool HasNodeConnection	(	GridNode	node,
		int	dir
	)

HasNodeConnection() [2/2]

bool HasNodeConnection	(	int	index,
		int	x,
		int	z,
		int	dir
	)

IsValidConnection()

virtual bool IsValidConnection ( GridNodeBase  node1, GridNodeBase  node2  )

virtual

Returns true if a connection between the adjacent nodes n1 and n2 is valid.

Also takes into account if the nodes are walkable.

This method may be overriden if you want to customize what connections are valid. It must however hold that IsValidConnection(a,b) == IsValidConnection(b,a).

This is used for calculating the connections when the graph is scanned or updated.

See also

CalculateConnections

Linecast() [1/4]

bool Linecast	(	Vector3	from,
		Vector3	to
	)

Returns if there is an obstacle between from and to on the graph.

This is not the same as Physics.Linecast, this function traverses the graph and looks for collisions.

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 IRaycastableGraph.

Linecast() [2/4]

bool Linecast	(	Vector3	from,
		Vector3	to,
		GraphNode	hint
	)

Returns if there is an obstacle between from and to on the graph.

Parameters

[in]	from	Point to linecast from
[in]	to	Point to linecast to
[in]	hint	If you have some idea of what the start node might be (the one close to from), pass it to hint since it can enable faster lookups

This is not the same as Physics.Linecast, this function traverses the graph and looks for collisions.

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 IRaycastableGraph.

Linecast() [3/4]

bool Linecast	(	Vector3	from,
		Vector3	to,
		GraphNode	hint,
		out GraphHitInfo	hit
	)

Returns if there is an obstacle between from and to on the graph.

Parameters

[in]	from	Point to linecast from
[in]	to	Point to linecast to
[out]	hit	Contains info on what was hit, see GraphHitInfo
[in]	hint	If you have some idea of what the start node might be (the one close to _a), pass it to hint since it can enable faster lookups

This is not the same as Physics.Linecast, this function traverses the graph and looks for collisions.

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 IRaycastableGraph.

Linecast() [4/4]

bool Linecast	(	Vector3	from,
		Vector3	to,
		GraphNode	hint,
		out GraphHitInfo	hit,
		List< GraphNode >	trace
	)

Returns if there is an obstacle between from and to on the graph.

Parameters

[in]	from	Point to linecast from
[in]	to	Point to linecast to
[out]	hit	Contains info on what was hit, see GraphHitInfo
[in]	hint	This parameter is deprecated. It will be ignored.
	trace	If a list is passed, then it will be filled with all nodes the linecast traverses

This is not the same as Physics.Linecast, this function traverses the graph and looks for collisions.

It uses a method similar to Bresenham's line algorithm but it has been extended to allow the start and end points to lie on non-integer coordinates (which makes the math a bit trickier).

See also

https://en.wikipedia.org/wiki/Bresenham's_line_algorithm

Version

In 3.6.8 this method was rewritten to improve accuracy and performance. Previously it used a sampling approach which could cut corners of obstacles slightly and was pretty inefficient.

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 IRaycastableGraph.

OnDestroy()

override void OnDestroy ( )

protectedvirtual

This function will be called when this graph is destroyed.

Reimplemented from NavGraph.

Reimplemented in LayerGridGraph.

OnDrawGizmos()

override void OnDrawGizmos ( RetainedGizmos  gizmos, bool  drawNodes  )

virtual

Draw gizmos for the graph.

Reimplemented from NavGraph.

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.

Reimplemented in LayerGridGraph.

RecalculateCell()

virtual void RecalculateCell ( int  x, int  z, bool  resetPenalties = true, bool  resetTags = true  )

virtual

Recalculates single node in the graph.

For a layered grid graph this will recalculate all nodes at a specific (x,z) cell in the grid. For grid graphs this will simply recalculate the single node at those coordinates.

Parameters

x	X coordinate of the cell
z	Z coordinate of the cell
resetPenalties	If true, the penalty of the nodes will be reset to the initial value as if the graph had just been scanned (this excludes texture data however which is only done when scanning the graph).
resetTags	If true, the tag will be reset to zero (the default tag).

Note

This must only be called when it is safe to update nodes. For example when scanning the graph or during a graph update.

This will not recalculate any connections as this method is often run for several adjacent nodes at a time. After you have recalculated all the nodes you will have to recalculate the connections for the changed nodes as well as their neighbours.

See also

CalculateConnections

Reimplemented in LayerGridGraph.

RelocateNodes() [1/2]

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.

RelocateNodes() [2/2]

void RelocateNodes	(	Vector3	center,
		Quaternion	rotation,
		float	nodeSize,
		float	aspectRatio = 1,
		float	isometricAngle = 0
	)

Relocate the grid graph using new settings.

This will move all nodes in the graph to new positions which matches the new settings.

RemoveGridGraphFromStatic()

void RemoveGridGraphFromStatic ( )

private

ScanInternal()

override IEnumerable<Progress> 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.

Reimplemented in LayerGridGraph.

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.

Reimplemented in LayerGridGraph.

SetDimensions()

void SetDimensions	(	int	width,
		int	depth,
		float	nodeSize
	)

Updates unclampedSize from width, depth and nodeSize values.

Also generates a new matrix .

Note

This does not rescan the graph, that must be done with Scan

You should use this method instead of setting the width and depth fields as the grid dimensions are not defined by the width and depth variables but by the unclampedSize and center variables.

        var gg = AstarPath.active.data.gridGraph;
        var width = 80;
        var depth = 60;
        var nodeSize = 1.0f;

        gg.SetDimensions(width, depth, nodeSize);

        // Recalculate the graph
        AstarPath.active.Scan();

SetNodeConnection() [1/2]

void SetNodeConnection	(	GridNode	node,
		int	dir,
		bool	value
	)

SetNodeConnection() [2/2]

void SetNodeConnection	(	int	index,
		int	x,
		int	z,
		int	dir,
		bool	value
	)

Set if connection in the specified direction should be enabled.

Note that bounds checking will still be done when getting the connection value again, so it is not necessarily true that HasNodeConnection will return true just because you used SetNodeConnection on a node to set a connection to true.

Parameters

index	Index of the node
x	X coordinate of the node
z	Z coordinate of the node
dir	Direction from 0 up to but excluding 8.
value	Enable or disable the connection

Note

This is identical to Pathfinding.Node.SetConnectionInternal

Deprecated:

SetUpOffsetsAndCosts()

virtual void SetUpOffsetsAndCosts ( )

virtual

Sets up neighbourOffsets with the current settings.

neighbourOffsets, neighbourCosts, neighbourXOffsets and neighbourZOffsets are set up.
The cost for a non-diagonal movement between two adjacent nodes is RoundToInt (nodeSize * Int3.Precision)
The cost for a diagonal movement between two adjacent nodes is RoundToInt (nodeSize * Sqrt (2) * Int3.Precision)

SnappedLinecast()

bool SnappedLinecast	(	Vector3	from,
		Vector3	to,
		GraphNode	hint,
		out GraphHitInfo	hit
	)

Returns if there is an obstacle between from and to on the graph.

This function is different from the other Linecast functions since it 1) snaps the start and end positions directly to the graph.

Parameters

[in]	from	Point to linecast from
[in]	to	Point to linecast to
[out]	hit	Contains info on what was hit, see GraphHitInfo
[in]	hint

UpdateArea()

void IUpdatableGraph. UpdateArea ( GraphUpdateObject  o )

private

Internal function to update an area of the graph.

Implements IUpdatableGraph.

UpdateAreaInit()

void IUpdatableGraph. UpdateAreaInit ( GraphUpdateObject  o )

private

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

See also

CanUpdateAsync

Implements IUpdatableGraph.

UpdateAreaPost()

void IUpdatableGraph. UpdateAreaPost ( GraphUpdateObject  o )

private

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

See also

CanUpdateAsync

Implements IUpdatableGraph.

UpdateNodePositionCollision()

virtual void UpdateNodePositionCollision ( GridNode  node, int  x, int  z, bool  resetPenalty = true  )

virtual

Updates position, walkability and penalty for the node.

Assumes that collision.Initialize (...) has been called before this function

Deprecated:

Use RecalculateCell instead which works both for grid graphs and layered grid graphs.

UpdateSizeFromWidthDepth()

void UpdateSizeFromWidthDepth

(

)

Updates unclampedSize from width, depth and nodeSize values.

Deprecated:

Use SetDimensions instead

UpdateTransform()

void UpdateTransform

(

)

Updates the transform field which transforms graph space to world space.

In graph space all nodes are laid out in the XZ plane with the first node having a corner in the origin. One unit in graph space is one node so the first node in the graph is at (0.5,0) the second one at (1.5,0) etc.

This takes the current values of the parameters such as position and rotation into account the transform that was used the last time the graph was scanned is stored in the transform field.

The transform field is calculated using this method when the graph is scanned. The width, depth variables are also updated based on the unclampedSize field.

Member Data Documentation

aspectRatio

float aspectRatio = 1F

Scaling of the graph along the X axis.

This should be used if you want different scales on the X and Y axis of the grid

center

Vector3 center

Center point of the grid.

collision

GraphCollision collision

Settings on how to check for walkability and height.

cutCorners

bool cutCorners = true

If disabled, will not cut corners on obstacles.

If connections is Eight, obstacle corners might be cut by a connection, setting this to false disables that.

depth

int depth

Depth (height) of the grid in nodes.

See also

SetDimensions

erodeIterations

int erodeIterations

Erosion of the graph.

The graph can be eroded after calculation. This means a margin is put around unwalkable nodes or other unwalkable connections. It is really good if your graph contains ledges where the nodes without erosion are walkable too close to the edge.

Below is an image showing a graph with erode iterations 0, 1 and 2

Note

A high number of erode iterations can seriously slow down graph updates during runtime (GraphUpdateObject) and should be kept as low as possible.

See also

erosionUseTags

erosionFirstTag

int erosionFirstTag = 1

Tag to start from when using tags for erosion.

See also

erosionUseTags

erodeIterations

erosionUseTags

bool erosionUseTags

Use tags instead of walkability for erosion.

Tags will be used for erosion instead of marking nodes as unwalkable. The nodes will be marked with tags in an increasing order starting with the tag erosionFirstTag. Debug with the Tags mode to see the effect. With this enabled you can in effect set how close different AIs are allowed to get to walls using the Valid Tags field on the Seeker component.

See also

erosionFirstTag

getNearestForceOverlap

const int getNearestForceOverlap = 2

In GetNearestForce, determines how far to search after a valid node has been found.

hexagonNeighbourIndices

readonly int [] hexagonNeighbourIndices = { 0, 1, 5, 2, 3, 7 }

staticpackage

Which neighbours are going to be used when neighbours=6.

isometricAngle

float isometricAngle

Angle to use for the isometric projection.

If you are making a 2D isometric game, you may want to use this parameter to adjust the layout of the graph to match your game. This will essentially scale the graph along one of its diagonals to produce something like this:

A perspective view of an isometric graph.

A top down view of an isometric graph. Note that the graph is entirely 2D, there is no perspective in this image.

Usually the angle that you want to use is either 30 degrees (alternatively 90-30 = 60 degrees) or atan(1/sqrt(2)) which is approximately 35.264 degrees (alternatively 90 - 35.264 = 54.736 degrees). You might also want to rotate the graph plus or minus 45 degrees around the Y axis to get the oritientation required for your game.

You can read more about it on the wikipedia page linked below.

See also

http://en.wikipedia.org/wiki/Isometric_projection

https://en.wikipedia.org/wiki/Isometric_graphics_in_video_games_and_pixel_art

rotation

maxClimb

float maxClimb = 0.4F

The max position difference between two nodes to enable a connection.

Set to 0 to ignore the value.

maxSlope

float maxSlope = 90

The max slope in degrees for a node to be walkable.

neighbourCosts

readonly uint [] neighbourCosts = new uint[8]

Costs to neighbour nodes.

neighbourOffsets

readonly int [] neighbourOffsets = new int[8]

Index offset to get neighbour nodes.

Added to a node's index to get a neighbour node index.

        Z
        |
        |

     6  2  5
      \ | /
--  3 - X - 1  ----- X
      / | \
     7  0  4

        |
        |

neighbours

NumNeighbours neighbours = NumNeighbours.Eight

Number of neighbours for each node.

Either four, six, eight connections per node.

Six connections is primarily for emulating hexagon graphs.

neighbourXOffsets

readonly int [] neighbourXOffsets = new int[8]

Offsets in the X direction for neighbour nodes.

Only 1, 0 or -1

neighbourZOffsets

readonly int [] neighbourZOffsets = new int[8]

Offsets in the Z direction for neighbour nodes.

Only 1, 0 or -1

nodes

GridNode [] nodes

All nodes in this graph.

Nodes are laid out row by row.

The first node has grid coordinates X=0, Z=0, the second one X=1, Z=0
the last one has grid coordinates X=width-1, Z=depth-1.

        var gg = AstarPath.active.data.gridGraph;
        int x = 5;
        int z = 8;
        GridNode node = gg.nodes[z*gg.width + x];

See also

GetNodes

nodeSize

float nodeSize = 1

Size of one node in world units.

See also

SetDimensions

penaltyAngle

bool penaltyAngle

penaltyAngleFactor

float penaltyAngleFactor = 100F

How much penalty is applied depending on the slope of the terrain.

At a 90 degree slope (not that exactly 90 degree slopes can occur, but almost 90 degree), this penalty is applied. At a 45 degree slope, half of this is applied and so on. Note that you may require very large values, a value of 1000 is equivalent to the cost of moving 1 world unit.

penaltyAnglePower

float penaltyAnglePower = 1

How much extra to penalize very steep angles.

penaltyPosition

bool penaltyPosition

Use position (y-coordinate) to calculate penalty.

penaltyPositionFactor

float penaltyPositionFactor = 1F

Scale factor for penalty when calculating from position.

See also

penaltyPosition

penaltyPositionOffset

float penaltyPositionOffset

Offset for the position when calculating penalty.

See also

penaltyPosition

rotation

Vector3 rotation

Rotation of the grid in degrees.

showMeshOutline

bool showMeshOutline = true

Show an outline of the grid nodes in the Unity Editor.

showMeshSurface

bool showMeshSurface = true

Show the surface of the graph.

Each node will be drawn as a square (unless e.g hexagon graph mode has been enabled).

showNodeConnections

bool showNodeConnections

Show the connections between the grid nodes in the Unity Editor.

textureData

TextureData textureData = new TextureData()

Holds settings for using a texture as source for a grid graph.

Texure data can be used for fine grained control over how the graph will look. It can be used for positioning, penalty and walkability control.
Below is a screenshot of a grid graph with a penalty map applied. It has the effect of the AI taking the longer path along the green (low penalty) areas.

Color data is got as 0...255 values.

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

Warning

Can only be used with Unity 3.4 and up

unclampedSize

Vector2 unclampedSize

Size of the grid.

Might be negative or smaller than nodeSize

uniformEdgeCosts

bool uniformEdgeCosts

If true, all edge costs will be set to the same value.

If false, diagonals will cost more. This is useful for a hexagon graph where the diagonals are actually the same length as the normal edges (since the graph has been skewed)

useJumpPointSearch

bool useJumpPointSearch

width

int width

Width of the grid in nodes.

See also

SetDimensions

Property Documentation

Depth

int Depth

getset

LayerCount

virtual int LayerCount

get

Number of layers in the graph.

For grid graphs this is always 1, for layered grid graphs it can be higher. The nodes array has the size width*depth*layerCount.

size

Vector2 size

getprotected set

Size of the grid.

Will always be positive and larger than nodeSize.

See also

UpdateTransform

transform

GraphTransform transform

getprivate set

Determines how the graph transforms graph space to world space.

See also

UpdateTransform

uniformWidthDepthGrid

virtual bool uniformWidthDepthGrid

get

This is placed here so generators inheriting from this one can override it and set it to false.

If it is true, it means that the nodes array's length will always be equal to width*depth It is used mainly in the editor to do auto-scanning calls, setting it to false for a non-uniform grid will reduce the number of scans

useRaycastNormal

bool useRaycastNormal

get

Use heigh raycasting normal for max slope calculation.

True if maxSlope is less than 90 degrees.

Width

int Width

getset

---

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

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