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 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.astarData;
// This creates a Grid Graph
GridGraph gg = data.AddGraph(typeof(GridGraph)) as GridGraph;
// Setup a grid graph with some values
gg.width = 50;
gg.depth = 50;
gg.nodeSize = 1;
gg.center = new Vector3 (10,0,0);
// Updates internal size from the above values
gg.UpdateSizeFromWidthDepth();
// Scans all graphs, do not call gg.Scan(), that is an internal method
AstarPath.active.Scan();

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

Public Member Functions
	GridGraph ()

virtual void	CalculateConnections (GridNode[] nodes, int x, int z, GridNode node)
	Calculates the grid connections for a single node.

GraphUpdateThreading	CanUpdateAsync (GraphUpdateObject o)

bool	CheckConnection (GridNode node, int dir)
	Returns if node is connected to it's neighbour in the specified direction.

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

virtual void	ErodeWalkableArea ()
	Erodes the walkable area.

virtual void	ErodeWalkableArea (int xmin, int zmin, int xmax, int zmax)
	Erodes the walkable area.

void	GenerateMatrix ()
	Generates the matrix used for translating nodes from grid coordinates to world coordintes.

uint	GetConnectionCost (int dir)

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

override NNInfo	GetNearestForce (Vector3 position, NNConstraint constraint)

GridNode	GetNodeConnection (GridNode node, int dir)

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

List< GraphNode >	GetNodesInArea (Bounds b)
	All nodes inside the bounding box.

List< GraphNode >	GetNodesInArea (GraphUpdateShape shape)
	All nodes inside the shape.

Int3	GraphPointToWorld (int x, int z, float height)
	Transform a point in graph space to world space.

bool	HasNodeConnection (GridNode node, int dir)

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

virtual bool	IsValidConnection (GridNode n1, GridNode n2)
	Returns true if a connection between the adjacent nodes n1 and n2 is valid.

bool	Linecast (Vector3 _a, Vector3 _b)
	Returns if there is an obstacle between origin and end on the graph.

bool	Linecast (Vector3 _a, Vector3 _b, GraphNode hint)
	Returns if there is an obstacle between origin and end on the graph.

bool	Linecast (Vector3 _a, Vector3 _b, GraphNode hint, out GraphHitInfo hit)
	Returns if there is an obstacle between origin and end on the graph.

bool	Linecast (Vector3 _a, Vector3 _b, GraphNode hint, out GraphHitInfo hit, List< GraphNode > trace)
	Returns if there is an obstacle between and on the graph.

override void	OnDestroy ()
	This function will be called when this graph is destroyed.

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

void	OnPostScan (AstarPath script)
	Auto links grid graphs together.

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

void	RelocateNodes (Vector3 center, Quaternion rotation, float nodeSize, float aspectRatio=1, float isometricAngle=0)
	Relocate the grid graph using new settings.

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

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

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.

virtual void	SetUpOffsetsAndCosts ()
	Sets up neighbourOffsets with the current settings.

bool	SnappedLinecast (Vector3 a, Vector3 b, GraphNode hint, out GraphHitInfo hit)
	Returns if there is an obstacle between and on the graph.

void	UpdateArea (GraphUpdateObject o)
	Internal function to update an area of the graph.

void	UpdateAreaInit (GraphUpdateObject o)

virtual void	UpdateNodePositionCollision (GridNode node, int x, int z, bool resetPenalty=true)
	Updates position, walkability and penalty for the node.

void	UpdateSizeFromWidthDepth ()
	Updates size from width, depth and nodeSize values.

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.

virtual int	CountNodes ()
	Count nodes in the graph.

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	RelocateNodes (Matrix4x4 oldMatrix, Matrix4x4 newMatrix)
	Relocates the nodes in this 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 Member Functions inherited from IRaycastableGraph
bool	Linecast (Vector3 start, Vector3 end)

bool	Linecast (Vector3 start, Vector3 end, GraphNode hint)

bool	Linecast (Vector3 start, Vector3 end, GraphNode hint, out GraphHitInfo hit)

bool	Linecast (Vector3 start, Vector3 end, GraphNode hint, out GraphHitInfo hit, List< GraphNode > trace)

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

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.

Public Attributes
const int	getNearestForceOverlap = 2
	In GetNearestForce, determines how far to search after a valid node has been found.

readonly uint[]	neighbourCosts = new uint[8]
	Costs to neighbour nodes.

readonly int[]	neighbourOffsets = new int[8]
	Index offset to get neighbour nodes.

readonly int[]	neighbourXOffsets = new int[8]
	Offsets in the X direction for neighbour nodes.

readonly int[]	neighbourZOffsets = new int[8]
	Offsets in the Z direction for neighbour nodes.

GridNode[]	nodes
	All nodes in this graph.

Public Attributes inherited from NavGraph
byte[]	_sguid
	Used to store the guid value.

AstarPath	active
	Reference to the AstarPath object in the scene.

bool	drawGizmos = true

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

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
bool	ClipLineSegmentToBounds (Vector3 a, Vector3 b, out Vector3 outA, out Vector3 outB)
	Clips a line segment in graph space to the graph bounds.

virtual GridNodeBase	GetNeighbourAlongDirection (GridNodeBase node, int direction)
	Utility method used by Linecast.

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

static void	GetBoundsMinMax (Bounds b, Matrix4x4 matrix, out Vector3 min, out Vector3 max)
	Calculates minimum and maximum points for bounds b when multiplied with the matrix.

Protected Attributes
int[]	corners
	Small buffer to reduce memory allocations.

Properties
Matrix4x4	boundsMatrix `[get, set]`

int	Depth `[get, set]`

Vector2	size `[get, set]`
	Size of the grid.

virtual bool	uniformWidthDepthGrid `[get]`
	This is placed here so generators inheriting from this one can override it and set it to false.

int	Width `[get, set]`

Properties inherited from NavGraph
Guid	guid `[get, set]`
	Used as an ID of the graph, considered to be unique.

Private Member Functions
bool	ErosionAnyFalseConnections (GridNode node)
	True if the node has any blocked connections.

GridNode	GetNodeConnection (int index, int x, int z, int dir)
	Get the connecting node from the node at (x,z) in the specified direction.

List< GraphNode >	GetNodesInArea (Bounds b, GraphUpdateShape shape)
	All nodes inside the shape or if null, the bounding box.

void	RemoveGridGraphFromStatic ()

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

Inspector - Settings
bool	useRaycastNormal `[get]`
	Use heigh raycasting normal for max slope calculation.

int	width
	Width of the grid in nodes.

int	depth
	Depth (height) of the grid in nodes.

float	aspectRatio = 1F
	Scaling of the graph along the X axis.

float	isometricAngle
	Angle to use for the isometric projection.

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

Vector3	rotation
	Rotation of the grid in degrees.

Bounds	bounds

Vector3	center
	Center point of the grid.

Vector2	unclampedSize
	Size of the grid.

float	nodeSize = 1
	Size of one node in world units.

GraphCollision	collision
	Settings on how to check for walkability and height.

float	maxClimb = 0.4F
	The max position difference between two nodes to enable a connection.

int	maxClimbAxis = 1
	The axis to use for maxClimb.

float	maxSlope = 90
	The max slope in degrees for a node to be walkable.

int	erodeIterations
	Erosion of the graph.

bool	erosionUseTags
	Use tags instead of walkability for erosion.

int	erosionFirstTag = 1
	Tag to start from when using tags for erosion.

bool	autoLinkGrids
	Auto link the graph's edge nodes together with other GridGraphs in the scene on Scan.

float	autoLinkDistLimit = 10F
	Distance limit for grid graphs to be auto linked.

NumNeighbours	neighbours = NumNeighbours.Eight
	Number of neighbours for each node.

bool	cutCorners = true
	If disabled, will not cut corners on obstacles.

float	penaltyPositionOffset
	Offset for the position when calculating penalty.

bool	penaltyPosition
	Use position (y-coordinate) to calculate penalty.

float	penaltyPositionFactor = 1F
	Scale factor for penalty when calculating from position.

bool	penaltyAngle

float	penaltyAngleFactor = 100F
	How much penalty is applied depending on the slope of the terrain.

float	penaltyAnglePower = 1
	How much extra to penalize very steep angles.

bool	useJumpPointSearch

TextureData	textureData = new TextureData ()
	Holds settings for using a texture as source for a grid graph.

Constructor & Destructor Documentation

GridGraph ( )

Member Function Documentation

static void CalculateConnections ( GridNode node )

static

Calculates the grid connections for a single node.

Convenience function, it's faster to use CalculateConnections(GridNode[],int,int,node) but that will only show when calculating for a large number of nodes.

Todo:: Test this function, should work ok, but you never know

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

virtual

Calculates the grid connections for a single node.

GraphUpdateThreading CanUpdateAsync ( GraphUpdateObject o )

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

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.

static float CrossMagnitude	(	Vector2	a,
		Vector2	b
	)

staticprotected

Magnitude of the cross product a x b.

override void DeserializeExtraInfo ( GraphSerializationContext ctx )

virtual

Deserializes graph type specific node data.

See Also: SerializeExtraInfo

Reimplemented from NavGraph.

Reimplemented in LayerGridGraph.

virtual void ErodeWalkableArea ( )

virtual

Erodes the walkable area.

See Also: erodeIterations

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

virtual

Erodes the walkable area.

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

See Also: erodeIterations

Reimplemented in LayerGridGraph.

bool ErosionAnyFalseConnections ( GridNode node )

private

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.

void GenerateMatrix ( )

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

static void GetBoundsMinMax	(	Bounds	b,
		Matrix4x4	matrix,
		out Vector3	min,
		out Vector3	max
	)

staticprotected

Calculates minimum and maximum points for bounds b when multiplied with the matrix.

uint GetConnectionCost ( int dir )

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

virtual

Todo:: Set clamped position for Grid Graph

Reimplemented from NavGraph.

Reimplemented in LayerGridGraph.

override NNInfo GetNearestForce	(	Vector3	position,
		NNConstraint	constraint
	)

virtual

Todo:: Set clamped position for Grid Graph

Reimplemented from NavGraph.

Reimplemented in LayerGridGraph.

virtual GridNodeBase GetNeighbourAlongDirection	(	GridNodeBase	node,
		int	direction
	)

protectedvirtual

Utility method used by Linecast.

Required since LevelGridNode does not inherit from GridNode. Lots of ugly casting but it was better than massive code duplication.

Returns null if the node has no connection in that direction.

Reimplemented in LayerGridGraph.

GridNode GetNodeConnection	(	GridNode	node,
		int	dir
	)

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

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.

Reimplemented in LayerGridGraph.

List<GraphNode> GetNodesInArea ( Bounds b )

All nodes inside the bounding box.

Note: Be nice to the garbage collector and release the list when you have used it (optional)

See Also: Pathfinding.Util.ListPool; GetNodesInArea(GraphUpdateShape)

List<GraphNode> GetNodesInArea ( GraphUpdateShape shape )

All nodes inside the shape.

Note: Be nice to the garbage collector and release the list when you have used it (optional)

See Also: Pathfinding.Util.ListPool; GetNodesInArea(Bounds)

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

private

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

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.

bool HasNodeConnection	(	GridNode	node,
		int	dir
	)

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

virtual bool IsValidConnection	(	GridNode	n1,
		GridNode	n2
	)

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)

bool Linecast	(	Vector3	_a,
		Vector3	_b
	)

Returns if there is an obstacle between origin and end 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

bool Linecast	(	Vector3	_a,
		Vector3	_b,
		GraphNode	hint
	)

Returns if there is an obstacle between origin and end on the graph.

Parameters

[in]	_a	Point to linecast from
[in]	_b	Point to linecast to
[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

bool Linecast	(	Vector3	_a,
		Vector3	_b,
		GraphNode	hint,
		out GraphHitInfo	hit
	)

Returns if there is an obstacle between origin and end on the graph.

Parameters

[in]	_a	Point to linecast from
[in]	_b	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

bool Linecast	(	Vector3	_a,
		Vector3	_b,
		GraphNode	hint,
		out GraphHitInfo	hit,
		List< GraphNode >	trace
	)

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

Parameters

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

Deprecated:

Parameters

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

override void OnDestroy ( )

virtual

This function will be called when this graph is destroyed.

Reimplemented from NavGraph.

Reimplemented in LayerGridGraph.

override void OnDrawGizmos ( bool drawNodes )

virtual

Draw gizmos for the graph.

Reimplemented from NavGraph.

Reimplemented in LayerGridGraph.

void OnPostScan ( AstarPath script )

Auto links grid graphs together.

Called after all graphs have been scanned.

See Also: autoLinkGrids

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.

Reimplemented in LayerGridGraph.

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.

Warning: This method is lossy, so calling it many times may cause node positions to lose precision. For example if you set the nodeSize 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 nodeSize 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.

void RemoveGridGraphFromStatic ( )

private

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.

Reimplemented in LayerGridGraph.

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.

Reimplemented in LayerGridGraph.

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.

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
value	Enable or disable the connection

Note: This is identical to Pathfinding.Node.SetConnectionInternal

Deprecated:

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)

bool SnappedLinecast	(	Vector3	a,
		Vector3	b,
		GraphNode	hint,
		out GraphHitInfo	hit
	)

Returns if there is an obstacle between and 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]	_a	Point to linecast from
[in]	_b	Point to linecast to
[out]	hit	Contains info on what was hit, see GraphHitInfo
[in]	hint

Deprecated:

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

Version: Since 3.6.8 this method uses the same implementation as the other linecast methods so there is no performance boost to using it.; In 3.6.8 this method was rewritten and that fixed a large number of bugs. Previously it had not always followed the line exactly as it should have and the hit output was not very accurate (for example the hit point was just the node position instead of a point on the edge which was hit)

void UpdateArea ( GraphUpdateObject o )

Internal function to update an area of the graph.

void UpdateAreaInit ( GraphUpdateObject o )

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

void UpdateSizeFromWidthDepth ( )

Updates size from width, depth and nodeSize values.

Also generates a new matrix .

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

Member Data Documentation

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

float autoLinkDistLimit = 10F

Distance limit for grid graphs to be auto linked.

Warning: This feature is experimental and it is currently disabled.

See Also: autoLinkGrids

bool autoLinkGrids

Auto link the graph's edge nodes together with other GridGraphs in the scene on Scan.

Warning: This feature is experimental and it is currently disabled.

See Also: autoLinkDistLimit

Bounds bounds

Vector3 center

Center point of the grid.

GraphCollision collision

Settings on how to check for walkability and height.

int [] corners

protected

Small buffer to reduce memory allocations.

Used in the CalculateConnections function

See Also: CalculateConnections

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.

int depth

Depth (height) of the grid in nodes.

See Also: UpdateSizeFromWidthDepth

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

int erosionFirstTag = 1

Tag to start from when using tags for erosion.

See Also: erosionUseTags; erodeIterations

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

const int getNearestForceOverlap = 2

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

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

staticprivate

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

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; rotation

float maxClimb = 0.4F

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

Set to 0 to ignore the value.

int maxClimbAxis = 1

The axis to use for maxClimb.

X = 0, Y = 1, Z = 2.

float maxSlope = 90

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

readonly uint [] neighbourCosts = new uint[8]

Costs to neighbour nodes.

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
        |
        |

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.

readonly int [] neighbourXOffsets = new int[8]

Offsets in the X direction for neighbour nodes.

Only 1, 0 or -1

readonly int [] neighbourZOffsets = new int[8]

Offsets in the Z direction for neighbour nodes.

Only 1, 0 or -1

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.

See Also: GetNodes

float nodeSize = 1

Size of one node in world units.

See Also: UpdateSizeFromWidthDepth

bool penaltyAngle

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.

float penaltyAnglePower = 1

How much extra to penalize very steep angles.

bool penaltyPosition

Use position (y-coordinate) to calculate penalty.

float penaltyPositionFactor = 1F

Scale factor for penalty when calculating from position.

See Also: penaltyPosition

float penaltyPositionOffset

Offset for the position when calculating penalty.

See Also: penaltyPosition

Vector3 rotation

Rotation of the grid in degrees.

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

Vector2 unclampedSize

Size of the grid.

Might be negative or smaller than nodeSize

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)

bool useJumpPointSearch

int width

Width of the grid in nodes.

See Also: UpdateSizeFromWidthDepth

Property Documentation

Matrix4x4 boundsMatrix

getset

int Depth

getset

Vector2 size

getset

Size of the grid.

Will always be positive and larger than nodeSize.

See Also: GenerateMatrix

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

bool useRaycastNormal

get

Use heigh raycasting normal for max slope calculation.

True if maxSlope is less than 90 degrees.

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

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