A* Pathfinding Project  4.1.9
The A* Pathfinding Project for Unity 3D
Pathfinding Namespace Reference


namespace  Examples
namespace  Legacy
namespace  Recast
namespace  RVO
 Local avoidance related classes.
namespace  Serialization
namespace  Util
namespace  Voxels
namespace  WindowsStore


class  ABPath
 Basic path, finds the shortest path from A to B. More...
class  ABPathEndingCondition
 Ending condition which emulates the default one for the ABPath. More...
class  AdvancedSmooth
 Smoothing by dividing path into turns and straight segments. More...
class  AIBase
 Base class for AIPath and RichAI. More...
class  AIDestinationSetter
 Sets the destination of an AI to the position of a specified object. More...
class  AILerp
 Linearly interpolating movement script. More...
class  AILerpEditor
class  AIPath
 AI for following paths. More...
class  AlternativePath
 Applies penalty to the paths it processes telling other units to avoid choosing the same path. More...
class  AnimationLink
class  AnimationLinkEditor
class  AstarColor
 Stores editor colors. More...
class  AstarData
 Stores the navigation graphs for the A* Pathfinding System. More...
class  AstarDebugger
 Debugger for the A* Pathfinding Project. More...
class  AstarMath
 Utility functions for working with numbers and strings. More...
class  AstarPathEditor
class  AstarProfiler
class  AstarSplines
 Contains various spline functions. More...
class  AstarUpdateChecker
 Handles update checking for the A* Pathfinding Project. More...
class  AstarUpdateWindow
struct  AstarWorkItem
 An item of work that can be executed when graphs are safe to update. More...
class  BaseAIEditor
class  BBTree
 Axis Aligned Bounding Box Tree. More...
class  BinaryHeap
 Binary heap implementation. More...
class  BlockManager
 Manager for blocker scripts such as SingleNodeBlocker. More...
struct  Connection
 Represents a connection to another node. More...
class  ConstantPath
 Finds all nodes within a specified distance from the start. More...
class  CustomGraphEditorAttribute
 Added to editors of custom graph types. More...
class  CustomPath
class  DebugUtility
 Helper for drawing debug information for the recast graph. More...
class  DefaultITraversalProvider
 Convenience class to access the default implementation of the ITraversalProvider. More...
class  DynamicGridObstacle
 Attach this script to any obstacle with a collider to enable dynamic updates of the graphs around it. More...
class  EditorBase
 Helper for creating editors. More...
class  EditorGUILayoutx
 Handles fading effects and also some custom GUI functions such as LayerMaskField. More...
class  EndingConditionDistance
 Target is found when the path is longer than a specified value. More...
class  EndingConditionProximity
 Ending condition which stops a fixed distance from the target point. More...
class  EnumFlagAttribute
class  EnumFlagDrawer
class  EuclideanEmbedding
 Implements heuristic optimizations. More...
class  FadeArea
 Editor helper for hiding and showing a group of GUI elements. More...
class  FleePath
 Returns a path heading away from a specified point to avoid. More...
class  FloodPath
 Floods the area completely for easy computation of any path to a single point. More...
class  FloodPathConstraint
 Restrict suitable nodes by if they have been searched by a FloodPath. More...
class  FloodPathTracer
 Traces a path created with the Pathfinding.FloodPath. More...
class  Funnel
 Implements the funnel algorithm as well as various related methods. More...
class  FunnelModifier
 Simplifies paths on navmesh graphs using the funnel algorithm. More...
class  GraphCollision
 Handles collision checking for graphs. More...
class  GraphEditor
class  GraphEditorBase
 Defined here only so non-editor classes can use the target field. More...
struct  GraphHitInfo
 Returned by graph ray- or linecasts containing info about the hit. More...
class  GraphModifier
 GraphModifier is used for modifying graphs or processing graph data based on events. More...
class  GraphNode
 Base class for all nodes. More...
class  GraphUpdateObject
 Represents a collection of settings used to update nodes in a specific region of a graph. More...
class  GraphUpdateProcessor
class  GraphUpdateScene
 Helper class for easily updating graphs. More...
class  GraphUpdateSceneEditor
 Editor for GraphUpdateScene. More...
class  GraphUpdateShape
 Defines a shape for a Pathfinding.GraphUpdateObject. More...
class  GraphUpdateUtilities
 Contains useful functions for updating graphs. More...
class  GraphUtilities
 Contains utility methods for getting useful information out of graph. More...
class  GridGraph
 Generates a grid of nodes. More...
class  GridGraphEditor
class  GridNode
 Node used for the GridGraph. More...
class  GridNodeBase
 Base class for GridNode and LevelGridNode. More...
class  GUIUtilityx
 Simple GUI utility functions. More...
interface  IAstarAI
 Common interface for all movement scripts in the A* Pathfinding Project. More...
interface  IGraphInternals
 Exposes internal methods for graphs. More...
interface  INavmesh
interface  INavmeshHolder
 Interface for something that holds a triangle based navmesh. More...
struct  Int2
 Two Dimensional Integer Coordinate Pair. More...
struct  Int3
 Holds a coordinate in integers. More...
struct  IntRect
 Integer Rectangle. More...
interface  IPathInternals
 Used for hiding internal methods of the Path class. More...
interface  IPathModifier
 Base for all path modifiers. More...
interface  IRaycastableGraph
 Graph which supports the Linecast method. More...
interface  ITransformedGraph
 Graph which has a well defined transformation from graph space to world space. More...
interface  ITraversalProvider
 Provides additional traversal information to a path request. More...
interface  IUpdatableGraph
 Graphs which can be updated during runtime. More...
interface  IVersionedMonoBehaviourInternal
 Exposes internal methods from Pathfinding.VersionedMonoBehaviour. More...
interface  IWorkItemContext
 Interface to expose a subset of the WorkItemProcessor functionality. More...
class  LayerGridGraph
 Grid Graph, supports layered worlds. More...
class  LayerGridGraphEditor
class  LayerGridGraphUpdate
 GraphUpdateObject with more settings for the LayerGridGraph. More...
class  LevelGridNode
 Describes a single node for the LayerGridGraph. More...
class  LinkedLevelNode
 Internal class used by the LayerGridGraph. More...
class  LocalSpaceGraph
 Helper for Pathfinding.Examples.LocalSpaceRichAI. More...
class  MeshNode
class  MonoModifier
 Base class for path modifiers which can be attached to GameObjects. More...
class  MultiTargetPath
 A path which searches from one point to a number of different targets in one search or from a number of different start points to a single target. More...
class  NavGraph
 Base class for all graphs. More...
class  NavmeshAdd
 Adds new geometry to a recast graph. More...
class  NavmeshBase
 Base class for RecastGraph and NavMeshGraph. More...
class  NavmeshClamp
 Attach to any GameObject and the object will be clamped to the navmesh. More...
class  NavmeshClipper
 Base class for the NavmeshCut and NavmeshAdd components. More...
class  NavmeshCut
 Navmesh cutting is used for fast recast/navmesh graph updates. More...
class  NavmeshCutEditor
class  NavMeshGraph
 Generates graphs based on navmeshes. More...
class  NavMeshGraphEditor
class  NavmeshTile
class  NNConstraint
 Nearest node constraint. More...
struct  NNInfo
 Result of a nearest node query. More...
struct  NNInfoInternal
 Internal result of a nearest node query. More...
class  NodeLink
 Connects two nodes with a direct connection. More...
class  NodeLink2
 Connects two nodes via two intermediate point nodes. More...
class  NodeLink3
 Connects two TriangleMeshNodes (recast/navmesh graphs) as if they had shared an edge. More...
class  NodeLink3Node
class  ObjImporter
class  OptimizationHandler
 Helper for enabling or disabling compiler directives. More...
class  Path
 Base class for all path types. More...
class  PathEndingCondition
 Customized ending condition for a path. More...
class  PathHandler
 Handles thread specific path data. More...
class  PathModifier
 Base class for path modifiers which are not attached to GameObjects. More...
class  PathNNConstraint
 A special NNConstraint which can use different logic for the start node and end node in a path. More...
class  PathNode
 Stores temporary node data for a single pathfinding request. More...
class  PathPool
 Pools path objects to reduce load on the garbage collector. More...
class  PathProcessor
class  PathReturnQueue
class  PathUtilities
 Contains useful functions for working with paths and nodes. More...
class  Patrol
 Simple patrol behavior. More...
class  PointGraph
 Basic point graph. More...
class  PointGraphEditor
class  PointKDTree
 Represents a collection of GraphNodes. More...
class  PointNode
 Node used for the PointGraph. More...
class  Polygon
 Utility functions for working with polygons, lines, and other vector math. More...
class  ProceduralGridMover
 Moves a grid graph to follow a target. More...
class  Profile
struct  Progress
 Progress info for e.g a progressbar. More...
class  RadiusModifier
 Radius path modifier for offsetting paths. More...
class  RandomPath
 Finds a path in a random direction from the start node. More...
class  RaycastModifier
 Simplifies a path using raycasting. More...
class  RaycastModifierEditor
class  RecastBBTree
 Axis Aligned Bounding Box Tree. More...
class  RecastBBTreeBox
class  RecastGraph
 Automatically generates navmesh graphs based on world geometry. More...
class  RecastGraphEditor
 Editor for the RecastGraph. More...
class  RecastMeshObj
 Explicit mesh object for recast graphs. More...
class  RecastMeshObjEditor
class  RecastTileUpdate
 Updates the recast tile(s) it is in at start, needs RecastTileUpdateHandler. More...
class  RecastTileUpdateHandler
 Helper for easier fast updates to recast graphs. More...
class  RelevantGraphSurface
 Pruning of recast navmesh regions. More...
class  RichAI
 Advanced AI for navmesh based graphs. More...
class  RichFunnel
class  RichPath
class  RichPathPart
class  RichSpecial
class  RVONavmeshEditor
class  RVOSimulatorEditor
class  RVOSquareObstacleEditor
class  Seeker
 Handles path calls for a single unit. More...
class  SeekerEditor
class  SimpleSmoothModifier
 Modifier which smooths the path. More...
class  SingleNodeBlocker
 Blocks single nodes in a graph. More...
class  SmoothModifierEditor
class  StartEndModifier
 Adjusts start and end points of a path. More...
class  TargetMover
 Moves the target in example scenes. More...
class  ThreadControlQueue
 Queue of paths to be processed by the system. More...
class  TileHandlerHelper
 Helper for navmesh cut objects. More...
class  TriangleMeshNode
 Node represented by a triangle. More...
class  UniqueComponentAttribute
class  UnityReferenceHelper
 Helper class to keep track of references to GameObjects. More...
class  VectorMath
 Various vector math utility functions. More...
class  VersionedMonoBehaviour
 Base class for all components in the package. More...
class  WorkItemProcessor
class  XPath
 Extended Path. More...


using Math = System.Math
using Thread = System.Threading.Thread


enum  CloseToDestinationMode { Stop, ContinueToExactDestination }
 What to do when the character is close to the destination. More...
enum  ColliderType { Sphere, Capsule, Ray }
 Determines collision check shape. More...
enum  GraphDebugMode {
  Areas, G, H, F,
  Penalty, Connections, Tags
 What data to draw the graph debugging with. More...
enum  GraphUpdateThreading {
  UnityThread = 0, SeparateThread = 1 << 0, UnityInit = 1 << 1, UnityPost = 1 << 2,
  SeparateAndUnityInit = SeparateThread | UnityInit
enum  Heuristic { Manhattan, DiagonalManhattan, Euclidean, None }
 How to estimate the cost from to the destination. More...
enum  HeuristicOptimizationMode { None, Random, RandomSpreadOut, Custom }
enum  InspectorGridMode { Grid, IsometricGrid, Hexagonal, Advanced }
enum  NumNeighbours { Four, Eight, Six }
 Number of neighbours for a single grid node. More...
enum  PathCompleteState { NotCalculated = 0, Error = 1, Complete = 2, Partial = 3 }
 State of a path request. More...
enum  PathLog {
  None, Normal, Heavy, InGame,
 How path results are logged by the system. More...
enum  PathState {
  Created = 0, PathQueue = 1, Processing = 2, ReturnQueue = 3,
  Returned = 4
 Internal state of a path in the pipeline. More...
enum  RayDirection { Up, Down, Both }
 Determines collision check ray direction. More...
enum  Side : byte { Colinear = 0, Left = 1, Right = 2 }
 Indicates the side of a line that a point lies on. More...
enum  ThreadCount {
  AutomaticLowLoad = -1, AutomaticHighLoad = -2, None = 0, One = 1,
  Two, Three, Four, Five,
  Six, Seven, Eight
 Number of threads to use. More...


delegate void OnGraphDelegate (NavGraph graph)
delegate void OnPathDelegate (Path p)
delegate void OnScanDelegate (AstarPath script)
delegate void OnScanStatus (Progress progress)

Typedef Documentation

◆ Math

using Math = System.Math

◆ Thread

typedef System Threading Thread Thread

Enumeration Type Documentation

◆ CloseToDestinationMode

What to do when the character is close to the destination.


The character will stop as quickly as possible when within endReachedDistance (field that exist on most movement scripts) units from the destination.


The character will continue to the exact position of the destination.

◆ ColliderType

enum ColliderType

Determines collision check shape.

See also

Uses a Sphere, Physics.CheckSphere.

In 2D this is a circle instead.


Uses a Capsule, Physics.CheckCapsule.

This will behave identically to the Sphere mode in 2D.


Uses a Ray, Physics.Linecast.

In 2D this is a single point instead.

◆ GraphDebugMode

enum GraphDebugMode

What data to draw the graph debugging with.


◆ GraphUpdateThreading

enum GraphUpdateThreading

Call UpdateArea in the unity thread.

This is the default value. Not compatible with SeparateThread.


Call UpdateArea in a separate thread.

Not compatible with UnityThread.


Calls UpdateAreaInit in the Unity thread before everything else.


Calls UpdateAreaPost in the Unity thread after everything else.

This is used together with SeparateThread to apply the result of the multithreaded calculations to the graph without modifying it at the same time as some other script might be using it (e.g calling GetNearest).


Combination of SeparateThread and UnityInit.

◆ Heuristic

enum Heuristic

How to estimate the cost from to the destination.

The heuristic is the estimated cost from the current node to the target. The different heuristics have roughly the same performance except not using any heuristic at all (#None) which is usually significantly slower.

In the image below you can see a comparison of the different heuristic options for an 8-connected grid and for a 4-connected grid. Note that all paths within the green area will all have the same length. The only difference between the heuristics is which of those paths of the same length that will be chosen. Note that while the Diagonal Manhattan and Manhattan options seem to behave very differently on an 8-connected grid they only do it in this case because of very small rounding errors. Usually they behave almost identically on 8-connected grids.

Generally for a 4-connected grid graph the Manhattan option should be used as it is the true distance on a 4-connected grid. For an 8-connected grid graph the Diagonal Manhattan option is the mathematically most correct option, however the Euclidean option is often preferred, especially if you are simplifying the path afterwards using modifiers.

For any graph that is not grid based the Euclidean option is the best one to use.

See also
Wikipedia: A* search_algorithm

Manhattan distance.

See also

Manhattan distance, but allowing diagonal movement as well.

This option is currently hard coded for the XZ plane. It will be equivalent to Manhattan distance if you try to use it in the XY plane (i.e for a 2D game).

Ordinary distance.

See also

Use no heuristic at all.

This reduces the pathfinding algorithm to Dijkstra's algorithm. This is usually significantly slower compared to using a heuristic, which is why the A* algorithm is usually preferred over Dijkstra's algorithm. You may have to use this if you have a very non-standard graph. For example a world with a wraparound playfield (think Civilization or Asteroids) and you have custom links with a zero cost from one end of the map to the other end. Usually the A* algorithm wouldn't find the wraparound links because it wouldn't think to look in that direction.

See also

◆ HeuristicOptimizationMode


◆ InspectorGridMode

enum InspectorGridMode

◆ NumNeighbours

enum NumNeighbours

Number of neighbours for a single grid node.

The 'Six' item was added in 3.6.1

◆ PathCompleteState

enum PathCompleteState

State of a path request.


The path has not been calculated yet.

See also

The path calculation is done, but it failed.

See also

The path has been successfully calculated.


The path has been calculated, but only a partial path could be found.

See also

◆ PathLog

enum PathLog

How path results are logged by the system.


Does not log anything.

This is recommended for release since logging path results has a performance overhead.


Logs basic info about the paths.


Includes additional info.


Same as heavy, but displays the info in-game using GUI.


Same as normal, but logs only paths which returned an error.

◆ PathState

enum PathState

Internal state of a path in the pipeline.


◆ RayDirection

enum RayDirection

Determines collision check ray direction.


Casts the ray from the bottom upwards.


Casts the ray from the top downwards.


Casts two rays in both directions.

◆ Side

enum Side : byte

Indicates the side of a line that a point lies on.


The point lies exactly on the line.


The point lies on the left side of the line.


The point lies on the right side of the line.

◆ ThreadCount

enum ThreadCount

Number of threads to use.


Function Documentation

◆ OnGraphDelegate()

delegate void Pathfinding.OnGraphDelegate ( NavGraph  graph)

◆ OnPathDelegate()

delegate void Pathfinding.OnPathDelegate ( Path  p)

◆ OnScanDelegate()

delegate void Pathfinding.OnScanDelegate ( AstarPath  script)

◆ OnScanStatus()

delegate void Pathfinding.OnScanStatus ( Progress  progress)