RecastGraph Class Reference

Automatically generates navmesh graphs based on world geometry. More...

Inheritance diagram for RecastGraph:

Collaboration diagram for RecastGraph:

Classes
struct	ExtraMesh
struct	Int2
struct	SceneMesh

Public Member Functions
void	AddPortal (Node n1, Node n2, List< Vector3 > left, List< Vector3 > right)
void	BuildFunnelCorridor (List< Node > path, int startIndex, int endIndex, List< Vector3 > left, List< Vector3 > right)
bool	CollectMeshes (out MeshFilter[] filters, out ExtraMesh[] extraMeshes)
override Node[]	CreateNodes (int number)
	Creates a number of nodes with the correct type for the graph.
override void	DeserializeExtraInfo (byte[] bytes)
	Deserializes graph type specific node data.
void	DeSerializeNodes (Node[] nodes, AstarSerializer serializer)
void	DeSerializeSettings (AstarSerializer serializer)
override NNInfo	GetNearest (Vector3 position, NNConstraint constraint, Node hint)
	Returns the nearest node to a position using the specified NNConstraint.
override NNInfo	GetNearestForce (Vector3 position, NNConstraint constraint)
	Returns the nearest node to a position using the specified constraint.
List< MeshFilter >	GetSceneMeshes ()
bool	Linecast (Vector3 origin, Vector3 end)
bool	Linecast (Vector3 origin, Vector3 end, Node hint, out GraphHitInfo hit)
bool	Linecast (Vector3 origin, Vector3 end, Node hint)
override void	OnDrawGizmos (bool drawNodes)
override void	Scan ()
	Scans the graph, called from AstarPath.Scan Override this function to implement custom scanning logic
void	ScanCRecast ()
override byte[]	SerializeExtraInfo ()
	Serializes graph type specific node data.
void	SerializeNodes (Node[] nodes, AstarSerializer serializer)
void	SerializeSettings (AstarSerializer serializer)
void	SnapForceBoundsToScene ()
void	Sort (Int3[] a)
void	UpdateArea (GraphUpdateObject guo)
Public Member Functions inherited from NavGraph
virtual void	Awake ()
	This will be called on the same time as Awake on the gameObject which the AstarPath script is attached to.
NNInfo	GetNearest (Vector3 position)
	Returns the nearest node to a position using the default NNConstraint.
NNInfo	GetNearest (Vector3 position, NNConstraint constraint)
	Returns the nearest node to a position using the specified NNConstraint.
bool	InSearchTree (Node node, Path path)
	Returns if the node is in the search tree of the path.
virtual Color	NodeColor (Node node, NodeRunData data)
virtual void	OnDestroy ()
	Function for cleaning up references.
virtual void	PostDeserialization ()
	Called after all deserialization has been done for all graphs.
virtual void	RelocateNodes (Matrix4x4 oldMatrix, Matrix4x4 newMatrix)
	Relocates the nodes in this graph.
void	SafeOnDestroy ()
	SafeOnDestroy should be used when there is a risk that the pathfinding is searching through this graph when called
void	ScanGraph ()
	Consider using AstarPath.Scan () instead since this function might screw things up if there is more than one graph.
Public Member Functions inherited from ISerializableGraph
Node[]	CreateNodes (int num)
void	DeSerializeNodes (Node[] nodes, AstarSerializer serializer)
void	SerializeNodes (Node[] nodes, AstarSerializer serializer)
Public Member Functions inherited from ISerializableObject
void	DeSerializeSettings (AstarSerializer serializer)
	Called to deserialize the object.
void	SerializeSettings (AstarSerializer serializer)
	Called to serialize the object.
Public Member Functions inherited from IRaycastableGraph
bool	Linecast (Vector3 start, Vector3 end)
bool	Linecast (Vector3 start, Vector3 end, Node hint)
bool	Linecast (Vector3 start, Vector3 end, Node hint, out GraphHitInfo hit)
Public Member Functions inherited from IFunnelGraph
void	AddPortal (Node n1, Node n2, List< Vector3 > left, List< Vector3 > right)
	Add the portal between node n1 and n2 to the funnel corridor.
void	BuildFunnelCorridor (List< Node > path, int sIndex, int eIndex, List< Vector3 > left, List< Vector3 > right)
Public Member Functions inherited from IUpdatableGraph
void	UpdateArea (GraphUpdateObject o)
	Updates an area using the specified GraphUpdateObject.

Static Public Member Functions
static string	GetRecastPath ()

Public Attributes
bool	accurateNearestNode = true
	More accurate nearest node queries.
float	cellHeight = 0.4F
	Voxel sample size (y)
float	cellSize = 0.5F
	Voxel sample size (x,z)
float	characterRadius = 0.5F
float	contourMaxError = 2F
	Max distance from simplified edge to real edge.
Vector3	forcedBoundsCenter
	Center of the bounding box.
Vector3	forcedBoundsSize = new Vector3 (100,40,100)
	Size of the bounding box.
bool	includeOutOfBounds = false
bool	includeTerrain = true
	Include the Terrain in the scene.
LayerMask	mask = -1
	Masks which objects to include.
float	maxEdgeLength = 20
	Longer edges will be subdivided.
float	maxSlope = 30
	Max slope in degrees the character can traverse.
int	regionMinSize = 8
bool	showMeshOutline = false
	Show an outline of the polygons in the Unity Editor.
int	terrainSampleSize = 3
	Controls how large the sample size for the terrain is.
bool	useCRecast = false
	Use a C++ version of Recast.
float	walkableClimb = 0.5F
	Height the character can climb.
float	walkableHeight = 2F
	Character height.
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
bool	infoScreenOpen
	Used in the editor to check if the info screen is open.
uint	initialPenalty = 0
Matrix4x4	matrix
	A matrix for translating/rotating/scaling the graph.
string	name
Node[]	nodes
	All nodes this graph contains.
bool	open
	Is the graph open in the editor

Properties
BBTree	bbTree [get, set]
Bounds	forcedBounds [get]
Vector3[]	vectorVertices [get]
Int3[]	vertices [get, set]
Properties inherited from NavGraph
Guid	guid [get, set]
	Used as an ID of the graph, considered to be unique.
Matrix4x4	inverseMatrix [get]
Properties inherited from INavmesh
BBTree	bbTree [get, set]
	Bounding Box Tree.
Int3[]	vertices [get, set]

Private Attributes
BBTree	_bbTree
	Bounding Box Tree.
Vector3[]	_vectorVertices
Int3[]	_vertices

Detailed Description

Automatically generates navmesh graphs based on world geometry.

The recast graph is based on Recast (http://code.google.com/p/recastnavigation/).
I have translated a good portion of it to C# to run it natively in Unity. The Recast process is described as follows:

• The voxel mold is build from the input triangle mesh by rasterizing the triangles into a multi-layer heightfield. Some simple filters are then applied to the mold to prune out locations where the character would not be able to move.
• The walkable areas described by the mold are divided into simple overlayed 2D regions. The resulting regions have only one non-overlapping contour, which simplifies the final step of the process tremendously.
• The navigation polygons are peeled off from the regions by first tracing the boundaries and then simplifying them. The resulting polygons are finally converted to convex polygons which makes them perfect for pathfinding and spatial reasoning about the level.

It works exactly like that in the C# version as well, except that everything is triangulated to triangles instead of n-gons. The recast generation process completely ignores colliders since it only works on an existing "polygon soup". This is usually a good thing though, because world geometry is usually more detailed than the colliders.

Exporting for manual editing

In the editor there is a button for exporting the generated graph to a .obj file. Usually the generation process is good enough for the game directly, but in some cases you might want to edit some minor details. So you can export the graph to a .obj file, open it in your favourite 3D application, edit it, and export it to a mesh which Unity can import. Then you assign that new mesh to the "Replacement Mesh" field right below the export button. That mesh will then be used to calculate the graph.

Since many 3D modelling programs use different axis systems (unity uses X=right, Y=up, Z=forward), it can be a bit tricky to get the rotation and scaling right. For blender for example, what you have to do is to first import the mesh using the .obj importer. Don't change anything related to axes in the settings. Then select the mesh, open the transform tab (usually the thin toolbar to the right of the 3D view) and set Scale -> Z to -1. If you transform it using the S (scale) hotkey, it seems to set both Z and Y to -1 of some reason. Then make the edits you need and export it as an .obj file to somewhere in the Unity project. But this time, edit the setting named "Forward" to "Z forward" (not -Z as it is per default).

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

override Node [] CreateNodes ( int  number )

virtual

Creates a number of nodes with the correct type for the graph.

This should not set the nodes array, only return the nodes. Called by graph generators and when deserializing a graph with nodes. Override this function if you do not use the default Pathfinding::Node class.

Reimplemented from NavGraph.

override void DeserializeExtraInfo ( byte[]  bytes )

virtual

Deserializes graph type specific node data.

See Also

SerializeExtraInfo

Reimplemented from NavGraph.

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

virtual

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

Parameters

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

Reimplemented from NavGraph.

override NNInfo GetNearestForce ( Vector3  position, NNConstraint  constraint  )

virtual

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

Parameters

position	A Vector3
constraint	A NNConstraint

Returns

A NNInfo. This function will only return an empty NNInfo if there is no nodes which comply with the specified constraint.

Reimplemented from NavGraph.

Here is the call graph for this function:

override void Scan ( )

virtual

Scans the graph, called from AstarPath.Scan Override this function to implement custom scanning logic

Implements NavGraph.

Here is the call graph for this function:

override byte [] SerializeExtraInfo ( )

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.
If null is returned from this function, the DeserializeExtraInfo function will not be called on load.

Reimplemented from NavGraph.

Member Data Documentation

BBTree _bbTree

private

Bounding Box Tree.

Enables really fast lookups of nodes.

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 accurateNearestNode = true

More accurate nearest node queries.

When on, looks for the closest point on every triangle instead of if point is inside the node triangle in XZ space. This is slower, but a lot better if your mesh contains overlaps (e.g bridges over other areas of the mesh). Note that for maximum effect the Full Get Nearest Node Search setting should be toggled in A* Inspector Settings.

Vector3 forcedBoundsCenter

Center of the bounding box.

Scanning will only be done inside the bounding box

Vector3 forcedBoundsSize = new Vector3 (100,40,100)

Size of the bounding box.

bool includeTerrain = true

Include the Terrain in the scene.

float maxEdgeLength = 20

Longer edges will be subdivided.

Reducing this value can improve path quality since similarly sized polygons yield better paths than really large and really small next to each other

int terrainSampleSize = 3

Controls how large the sample size for the terrain is.

A higher value is faster but less accurate

bool useCRecast = false

Use a C++ version of Recast.

The C++ version is faster and has more features, though right now the features are quite similar because I haven't added support for them yet.
The C++ version can only be used in the editor or in standalones and it requires a special file to be placed inside the executable for standalones.
When deploying for mac, the Recast file (which can be found in the AstarPathfindingProject folder) should be copied to a new folder myApplication.app/Contents/Recast/

When deploying for windows, the Recast file should be copied to the data folder/Recast/

You can however save a cache of the graph scanned in the editor and use that in a webplayer but you cannot rescann any graphs in the webplayer
I have no information on whether or not it would work using iPhone or Android, so I would refrain form trying to use it there (though you can still cache graphs as you can with the webplayer)

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

• /Users/aron/Unity/AstarPathfindingGIT/Assets/AstarPathfindingProject/Generators/RecastGenerator.cs