Class AstarPath Extends VersionedMonoBehaviour

bool IsAnyGraphUpdateInProgress

Returns if any graph updates are being calculated right now.

bool IsAnyGraphUpdateQueued

Returns if any graph updates are waiting to be applied.

bool IsAnyWorkItemInProgress

Returns if any work items are in progress right now.

bool IsUsingMultithreading

Returns whether or not multithreading is used.

int NumParallelThreads

Number of parallel pathfinders.

Returns the number of concurrent processes which can calculate paths at once. When using multithreading, this will be the number of threads, if not using multithreading it is always 1 (since only 1 coroutine is used).

bool batchGraphUpdates = false

Throttle graph updates and batch them to improve performance.

If toggled, graph updates will batched and executed less often (specified by graphUpdateBatchingInterval).

This can have a positive impact on pathfinding throughput since the pathfinding threads do not need to be stopped as often, and it reduces the overhead per graph update. All graph updates are still applied, they are just batched together so that more of them are applied at the same time.

Do not use this if you want minimal latency between a graph update being requested and it being applied.

This only applies to graph updates requested using the UpdateGraphs method. Not those requested using AddWorkItem.

If you want to apply graph updates immediately at some point, you can call FlushGraphUpdates.

AstarColor colorSettings

Reference to the color settings for this AstarPath object.

Color settings include for example which color the nodes should be in, in the sceneview.

AstarData data

Holds all graph data.

float debugFloor = 0

Low value to use for certain debugMode modes.

For example if debugMode is set to G, this value will determine when the node will be completely red.

GraphDebugMode debugMode

The mode to use for drawing nodes in the sceneview.

float debugRoof = 20000

High value to use for certain debugMode modes.

For example if debugMode is set to G, this value will determine when the node will be completely green.

For the penalty debug mode, the nodes will be colored green when they have a penalty less than debugFloor and red when their penalty is greater or equal to this value and something between red and green otherwise.

EuclideanEmbedding euclideanEmbedding = new EuclideanEmbedding()

Holds settings for heuristic optimization.

bool fullGetNearestSearch = false

Do a full GetNearest search for all graphs.

Additional searches will normally only be done on the graph which in the first fast search seemed to have the closest node. With this setting on, additional searches will be done on all graphs since the first check is not always completely accurate.
More technically: GetNearestForce on all graphs will be called if true, otherwise only on the one graph which's GetNearest search returned the best node.
Usually faster when disabled, but higher quality searches when enabled.

float graphUpdateBatchingInterval = 0.2F

Minimum number of seconds between each batch of graph updates.

If batchGraphUpdates is true, this defines the minimum number of seconds between each batch of graph updates.

This can have a positive impact on pathfinding throughput since the pathfinding threads do not need to be stopped as often, and it reduces the overhead per graph update. All graph updates are still applied however, they are just batched together so that more of them are applied at the same time.

Do not use this if you want minimal latency between a graph update being requested and it being applied.

This only applies to graph updates requested using the UpdateGraphs method. Not those requested using AddWorkItem.

NavGraph[] graphs

Shortcut to AstarData.graphs.

Heuristic heuristic = Heuristic.Euclidean

The distance function to use as a heuristic.

The heuristic, often referred to as just 'H' is the estimated cost from a node to the target. Different heuristics affect how the path picks which one to follow from multiple possible with the same length

float heuristicScale = 1F

The scale of the heuristic.

If a value lower than 1 is used, the pathfinder will search more nodes (slower). If 0 is used, the pathfinding algorithm will be reduced to dijkstra's algorithm. This is equivalent to setting heuristic to None. If a value larger than 1 is used the pathfinding will (usually) be faster because it expands fewer nodes, but the paths may no longer be the optimal (i.e the shortest possible paths).

Usually you should leave this to the default value of 1.

bool isScanning

True while any graphs are being scanned.

This is primarily relevant when scanning graph asynchronously.

float lastScanTime

The time it took for the last call to Scan to complete.

PathLog logPathResults = PathLog.Normal

The amount of debugging messages.

Use less debugging to improve performance (a bit) or just to get rid of the Console spamming. Use more debugging (heavy) if you want more information about what the pathfinding scripts are doing. The InGame option will display the latest path log using in-game GUI.

bool manualDebugFloorRoof = false

If set, the debugFloor and debugRoof values will not be automatically recalculated.

float maxFrameTime = 1F

Max number of milliseconds to spend on pathfinding during each frame.

At least 500 nodes will be searched each frame (if there are that many to search). When using multithreading this value is irrelevant.

float maxNearestNodeDistance = 100

Maximum distance to search for nodes.

When searching for the nearest node to a point, this is the limit (in world units) for how far away it is allowed to be.

This is relevant if you try to request a path to a point that cannot be reached and it thus has to search for the closest node to that point which can be reached (which might be far away). If it cannot find a node within this distance then the path will fail.

float maxNearestNodeDistanceSqr

Max Nearest Node Distance Squared.

NavmeshUpdates navmeshUpdates = new NavmeshUpdates()

Handles navmesh cuts.

OffMeshLinks offMeshLinks

Holds all active off-mesh links.

bool scanOnStartup = true

If true, all graphs will be scanned when the game starts, during OnEnable.

If you disable this, you will have to call AstarPath.active.Scan yourself to enable pathfinding. Alternatively you could load a saved graph from a file.

If a startup cache has been generated (see Saving and Loading Graphs), it always takes priority, and the graphs will be loaded from the cache instead of scanned.

This can be useful to disable if you want to scan your graphs asynchronously, or if you have a procedural world which has not been created yet at the start of the game.

bool showGraphs = false

Shows or hides graph inspectors.

Used internally by the editor

bool showNavGraphs = true

Visualize graphs in the scene view (editor only).

bool showSearchTree = false

If enabled, nodes will draw a line to their 'parent'.

This will show the search tree for the latest path.

bool showUnwalkableNodes = true

Toggle to show unwalkable nodes.

ThreadCount threadCount = ThreadCount.One

Number of pathfinding threads to use.

Multithreading puts pathfinding in another thread, this is great for performance on 2+ core computers since the framerate will barely be affected by the pathfinding at all.

• None indicates that the pathfinding is run in the Unity thread as a coroutine

• Automatic will try to adjust the number of threads to the number of cores and memory on the computer. Less than 512mb of memory or a single core computer will make it revert to using no multithreading.

It is recommended that you use one of the "Auto" settings that are available. The reason is that even if your computer might be beefy and have 8 cores. Other computers might only be quad core or dual core in which case they will not benefit from more than 1 or 3 threads respectively (you usually want to leave one core for the unity thread). If you use more threads than the number of cores on the computer it is mostly just wasting memory, it will not run any faster. The extra memory usage is not trivially small. Each thread needs to keep a small amount of data for each node in all the graphs. It is not the full graph data but it is proportional to the number of nodes. The automatic settings will inspect the machine it is running on and use that to determine the number of threads so that no memory is wasted.

The exception is if you only have one (or maybe two characters) active at time. Then you should probably just go with one thread always since it is very unlikely that you will need the extra throughput given by more threads. Keep in mind that more threads primarily increases throughput by calculating different paths on different threads, it will not calculate individual paths any faster.

float unwalkableNodeDebugSize = 0.3F

Size of the red cubes shown in place of unwalkable nodes.

string Branch = "master"

Which branch of the A* Pathfinding Project is this release.

Used when checking for updates so that users of the development versions can get notifications of development updates.

AstarDistribution Distribution = AstarDistribution.WebsiteDownload

Used by the editor to guide the user to the correct place to download updates.

System.Action On65KOverflow

Called when pathID overflows 65536 and resets back to zero.

System.Action OnAwakeSettings

Called on Awake before anything else is done.

This is called at the start of the Awake call, right after active has been set, but this is the only thing that has been done.
Use this when you want to set up default settings for an AstarPath component created during runtime since some settings can only be changed in Awake (such as multithreading related stuff) // Create a new AstarPath object on Start and apply some default settings
public void Start () {
AstarPath.OnAwakeSettings += ApplySettings;
AstarPath astar = gameObject.AddComponent<AstarPath>();
}

public void ApplySettings () {
// Unregister from the delegate
AstarPath.OnAwakeSettings -= ApplySettings;
// For example threadCount should not be changed after the Awake call
// so here's the only place to set it if you create the component during runtime
AstarPath.active.threadCount = ThreadCount.One;
}


OnGraphDelegate OnGraphPostScan

Called for each graph after they have been scanned.

All other graphs might not have been scanned yet. In most cases it is recommended to create a custom class which inherits from Pathfinding.GraphModifier instead.

OnGraphDelegate OnGraphPreScan

Called for each graph before they are scanned.

In most cases it is recommended to create a custom class which inherits from Pathfinding.GraphModifier instead.

OnScanDelegate OnGraphsUpdated

Called when any graphs are updated.

Register to for example recalculate the path whenever a graph changes. In most cases it is recommended to create a custom class which inherits from Pathfinding.GraphModifier instead.

OnScanDelegate OnLatePostScan

Called after scanning has completed fully.

This is called as the last thing in the Scan function. In most cases it is recommended to create a custom class which inherits from Pathfinding.GraphModifier instead.

OnPathDelegate OnPathPostSearch

Called for each path after searching.

Be careful when using multithreading since this will be called from a different thread.

OnPathDelegate OnPathPreSearch

Called for each path before searching.

Be careful when using multithreading since this will be called from a different thread.

System.Action OnPathsCalculated

Called right after callbacks on paths have been called.

A path's callback function runs on the main thread when the path has been calculated. This is done in batches for all paths that have finished their calculation since the last frame. This event will trigger right after a batch of callbacks have been called.

If you do not want to use individual path callbacks, you can use this instead to poll all pending paths and see which ones have completed. This is better than doing it in e.g. the Update loop, because here you will have a guarantee that all calculated paths are still valid. Immediately after this callback has finished, other things may invalidate calculated paths, like for example graph updates.

This is used by the ECS integration to update all entities' pending paths, without having to store a callback for each agent, and also to avoid the ECS synchronization overhead that having individual callbacks would entail.

OnScanDelegate OnPostScan

Called after scanning.

This is called before applying links, flood-filling the graphs and other post processing. In most cases it is recommended to create a custom class which inherits from Pathfinding.GraphModifier instead.

OnScanDelegate OnPreScan

Called before starting the scanning.

In most cases it is recommended to create a custom class which inherits from Pathfinding.GraphModifier instead.

System.Version Version = new System.Version(5, 2, 5)

The version number for the A* Pathfinding Project.

AstarPath active

Returns the active AstarPath object in the scene.

AstarDistribution

Information about where the package was downloaded.

bool IsInsideWorkItem

Returns if this code is currently being exectuted inside a work item.

In contrast to IsAnyWorkItemInProgress this is only true when work item code is being executed, it is not true in-between the updates to a work item that takes several frames to complete.

NNConstraint NNConstraintClosestAsSeenFromAbove = new NNConstraint() { constrainWalkability = false, constrainTags = false, constrainDistance = true, distanceMetric = DistanceMetric.ClosestAsSeenFromAbove(), }

Cached NNConstraint to avoid unnecessary allocations.

This should ideally be fixed by making NNConstraint an immutable class/struct.

IEnumerator<Progress> asyncScanTask

If an async scan is running, this will be set to the coroutine.

This primarily used to be able to force the async scan to complete immediately, if the AstarPath component should happen to be destroyed while an async scan is running.

PathHandler debugPathData

The path to debug using gizmos.

This is the path handler used to calculate the last path. It is used in the editor to draw debug information using gizmos.

ushort debugPathID

The path ID to debug using gizmos.

RWLock graphDataLock = new RWLock()

Global read-write lock for graph data.

Graph data is always consistent from the main-thread's perspective, but if you are using jobs to read from graph data, you may need this.

A write lock is held automatically...

• During graph updates. During async graph updates, the lock is only held once per frame while the graph update is actually running, not for the whole duration.

• During work items. Async work items work similarly to graph updates, the lock is only held once per frame while the work item is actually running.

• When GraphModifier events run.

• When graph related callbacks, such as OnGraphsUpdated, run.

• During the last step of a graph's scanning process. See ScanningStage.

To use e.g. AstarPath.active.GetNearest from an ECS job, you'll need to acquire a read lock first, and make sure the lock is only released when the job is finished.

var readLock = AstarPath.active.LockGraphDataForReading();
var handle = new MyJob {
// ...
}.Schedule(readLock.dependency);
readLock.UnlockAfter(handle);


bool graphUpdateRoutineRunning = false

GraphUpdateProcessor graphUpdates

Processes graph updates.

bool graphUpdatesWorkItemAdded = false

Makes sure QueueGraphUpdates will not queue multiple graph update orders.

bool hasScannedGraphAtStartup = false

HierarchicalGraph hierarchicalGraph

Holds a hierarchical graph to speed up some queries like if there is a path between two nodes.

string inGameDebugPath

Debug string from the last completed path.

Will be updated if logPathResults == PathLog.InGame

float lastGraphUpdate = -9999F

Time the last graph update was done.

Used to group together frequent graph updates to batches

ushort nextFreePathID = 1

The next unused Path ID.

Incremented for every call to GetNextPathID

GlobalNodeStorage nodeStorage

Holds global node data that cannot be stored in individual graphs.

PathProcessor pathProcessor

Holds all paths waiting to be calculated and calculates them.

PathReturnQueue pathReturnQueue

Holds all completed paths waiting to be returned to where they were requested.

RedrawScope redrawScope

string[] tagNames = null

Stored tag names.

int waitForPathDepth = 0

PathProcessor.GraphUpdateLock workItemLock

Held if any work items are currently queued.

WorkItemProcessor workItems

Processes work items.

bool prioritizeGraphs = false

Prioritize graphs.

Graphs will be prioritized based on their order in the inspector. The first graph which has a node closer than prioritizeGraphsLimit will be chosen instead of searching all graphs.

float prioritizeGraphsLimit = 1F

Distance limit for prioritizeGraphs.