A* Pathfinding Project
4.1.19
The A* Pathfinding Project for Unity 3D
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Helper class for easily updating graphs. More...
Helper class for easily updating graphs.
The GraphUpdateScene component is really easy to use. Create a new empty GameObject and add the component to it, it can be found in Components–>Pathfinding–>GraphUpdateScene.
When you have added the component, you should see something like the image below.
The above code will make it apply its changes to the graph (assuming a GraphUpdateScene component is attached to the same GameObject).
Next there is "Modify Walkability" and "Set Walkability" (which appears when "Modify Walkability" is toggled). If Modify Walkability is set, then all nodes inside the area will either be set to walkable or unwalkable depending on the value of the "Set Walkability" variable.
Penalty can also be applied to the nodes. A higher penalty (aka weight) makes the nodes harder to traverse so it will try to avoid those areas.
The tagging variables can be read more about on this page: Working with tags.
Public Member Functions | |
void | Apply () |
Updates graphs with a created GUO. More... | |
void | DisableLegacyMode () |
Disables legacy mode if it is enabled. More... | |
Bounds | GetBounds () |
Calculates the bounds for this component. More... | |
virtual void | InvertSettings () |
Inverts all invertable settings for this GUS. More... | |
void | LockToY () |
Lock all points to a specific Y value. More... | |
override void | OnPostScan () |
Called right after all graphs have been scanned. More... | |
void | RecalcConvex () |
Recalculate convex hull. More... | |
void | Start () |
Do some stuff at start. More... | |
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virtual void | OnGraphsPostUpdate () |
Called after graphs have been updated using GraphUpdateObjects. More... | |
virtual void | OnGraphsPreUpdate () |
Called before graphs are updated using GraphUpdateObjects. More... | |
virtual void | OnLatePostScan () |
Called at the end of the scanning procedure. More... | |
virtual void | OnPostCacheLoad () |
Called after cached graphs have been loaded. More... | |
virtual void | OnPreScan () |
Called right before graphs are going to be scanned. More... | |
Public Attributes | |
bool | applyOnScan = true |
Apply this graph update object whenever a graph is rescanned. More... | |
bool | applyOnStart = true |
Apply this graph update object on start. More... | |
bool | convex = true |
Use the convex hull of the points instead of the original polygon. More... | |
bool | legacyMode = false |
Emulates behavior from before version 4.0. More... | |
float | minBoundsHeight = 1 |
Minumum height of the bounds of the resulting Graph Update Object. More... | |
bool | modifyTag |
Should the tags of the nodes be modified. More... | |
bool | modifyWalkability |
If true, then all affected nodes will be made walkable or unwalkable according to setWalkability. More... | |
int | penaltyDelta |
Penalty to add to nodes. More... | |
Vector3 [] | points |
Points which define the region to update. More... | |
bool | resetPenaltyOnPhysics = true |
Reset penalties to their initial values when updating grid graphs and updatePhysics is true. More... | |
int | setTag |
If modifyTag is enabled, set all nodes' tags to this value. More... | |
bool | setWalkability |
Nodes will be made walkable or unwalkable according to this value if modifyWalkability is true. More... | |
bool | updateErosion = true |
Update Erosion for GridGraphs. More... | |
bool | updatePhysics |
Update node's walkability and connectivity using physics functions. More... | |
Protected Member Functions | |
override void | Awake () |
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override void | Awake () |
virtual void | OnDestroy () |
virtual void | OnDisable () |
Removes this modifier from list of active modifiers. More... | |
virtual void | OnEnable () |
Adds this modifier to list of active modifiers. More... | |
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virtual int | OnUpgradeSerializedData (int version, bool unityThread) |
Handle serialization backwards compatibility. More... | |
Private Member Functions | |
void | OnDrawGizmos () |
Draws some gizmos. More... | |
void | OnDrawGizmos (bool selected) |
Draws some gizmos. More... | |
void | OnDrawGizmosSelected () |
Draws some gizmos. More... | |
void | ToggleUseWorldSpace () |
Switches between using world space and using local space. More... | |
Private Attributes | |
Vector3 [] | convexPoints |
Private cached convex hull of the points. More... | |
bool | firstApplied |
Has apply been called yet. More... | |
bool | legacyUseWorldSpace |
Use world space for coordinates. More... | |
int | serializedVersion = 0 |
int | setTagInvert |
Private cached inversion of setTag. More... | |
Additional Inherited Members | |
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enum | EventType { PostScan = 1 << 0, PreScan = 1 << 1, LatePostScan = 1 << 2, PreUpdate = 1 << 3, PostUpdate = 1 << 4, PostCacheLoad = 1 << 5 } |
GraphModifier event type. More... | |
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static void | FindAllModifiers () |
static void | TriggerEvent (GraphModifier.EventType type) |
Triggers an event for all active graph modifiers. More... | |
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static List< T > | GetModifiersOfType< T > () |
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ulong | uniqueID |
Unique persistent ID for this component, used for serialization. More... | |
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static Dictionary< ulong, GraphModifier > | usedIDs = new Dictionary<ulong, GraphModifier>() |
Maps persistent IDs to the component that uses it. More... | |
void Apply | ( | ) |
Updates graphs with a created GUO.
Creates a Pathfinding.GraphUpdateObject with a Pathfinding.GraphUpdateShape representing the polygon of this object and update all graphs using AstarPath.UpdateGraphs. This will not update graphs immediately. See AstarPath.UpdateGraph for more info.
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protectedvirtual |
Reimplemented from VersionedMonoBehaviour.
void DisableLegacyMode | ( | ) |
Disables legacy mode if it is enabled.
Legacy mode is automatically enabled for components when upgrading from an earlier version than 3.8.6.
Bounds GetBounds | ( | ) |
Calculates the bounds for this component.
This is a relatively expensive operation, it needs to go through all points and run matrix multiplications.
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virtual |
Inverts all invertable settings for this GUS.
Namely: penalty delta, walkability, tags.
Penalty delta will be changed to negative penalty delta.
setWalkability will be inverted.
setTag will be stored in a private variable, and the new value will be 0. When calling this function again, the saved value will be the new value.
Calling this function an even number of times without changing any settings in between will be identical to no change in settings.
void LockToY | ( | ) |
Lock all points to a specific Y value.
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private |
Draws some gizmos.
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private |
Draws some gizmos.
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private |
Draws some gizmos.
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virtual |
Called right after all graphs have been scanned.
FloodFill and other post processing has not been done.
Reimplemented from GraphModifier.
void RecalcConvex | ( | ) |
Recalculate convex hull.
Will not do anything if convex is disabled.
void Start | ( | ) |
Do some stuff at start.
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private |
Switches between using world space and using local space.
bool applyOnScan = true |
Apply this graph update object whenever a graph is rescanned.
bool applyOnStart = true |
Apply this graph update object on start.
bool convex = true |
Use the convex hull of the points instead of the original polygon.
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private |
Private cached convex hull of the points.
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private |
Has apply been called yet.
Used to prevent applying twice when both applyOnScan and applyOnStart are enabled
bool legacyMode = false |
Emulates behavior from before version 4.0.
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private |
Use world space for coordinates.
If true, the shape will not follow when moving around the transform.
float minBoundsHeight = 1 |
Minumum height of the bounds of the resulting Graph Update Object.
Useful when all points are laid out on a plane but you still need a bounds with a height greater than zero since a zero height graph update object would usually result in no nodes being updated.
bool modifyTag |
Should the tags of the nodes be modified.
If enabled, set all nodes' tags to setTag
bool modifyWalkability |
If true, then all affected nodes will be made walkable or unwalkable according to setWalkability.
int penaltyDelta |
Penalty to add to nodes.
Usually you need quite large values, at least 1000-10000. A higher penalty means that agents will try to avoid those nodes more.
Be careful when setting negative values since if a node gets a negative penalty it will underflow and instead get really large. In most cases a warning will be logged if that happens.
Vector3 [] points |
Points which define the region to update.
bool resetPenaltyOnPhysics = true |
Reset penalties to their initial values when updating grid graphs and updatePhysics is true.
If you want to keep old penalties even when you update the graph you may want to disable this option.
The images below shows two overlapping graph update objects, the right one happened to be applied before the left one. They both have updatePhysics = true and are set to increase the penalty of the nodes by some amount.
The first image shows the result when resetPenaltyOnPhysics is false. Both penalties are added correctly.
This second image shows when resetPenaltyOnPhysics is set to true. The first GUO is applied correctly, but then the second one (the left one) is applied and during its updating, it resets the penalties first and then adds penalty to the nodes. The result is that the penalties from both GUOs are not added together. The green patch in at the border is there because physics recalculation (recalculation of the position of the node, checking for obstacles etc.) affects a slightly larger area than the original GUO bounds because of the Grid Graph -> Collision Testing -> Diameter setting (it is enlarged by that value). So some extra nodes have their penalties reset.
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private |
int setTag |
If modifyTag is enabled, set all nodes' tags to this value.
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private |
Private cached inversion of setTag.
Used for InvertSettings()
bool setWalkability |
Nodes will be made walkable or unwalkable according to this value if modifyWalkability is true.
bool updateErosion = true |
Update Erosion for GridGraphs.
When enabled, erosion will be recalculated for grid graphs after the GUO has been applied.
In the below image you can see the different effects you can get with the different values.
The first image shows the graph when no GUO has been applied. The blue box is not identified as an obstacle by the graph, the reason there are unwalkable nodes around it is because there is a height difference (nodes are placed on top of the box) so erosion will be applied (an erosion value of 2 is used in this graph). The orange box is identified as an obstacle, so the area of unwalkable nodes around it is a bit larger since both erosion and collision has made nodes unwalkable.
The GUO used simply sets walkability to true, i.e making all nodes walkable.
When updateErosion=True, the reason the blue box still has unwalkable nodes around it is because there is still a height difference so erosion will still be applied. The orange box on the other hand has no height difference and all nodes are set to walkable.
When updateErosion=False, all nodes walkability are simply set to be walkable in this example.
bool updatePhysics |
Update node's walkability and connectivity using physics functions.
For grid graphs, this will update the node's position and walkability exactly like when doing a scan of the graph. If enabled for grid graphs, modifyWalkability will be ignored.
For Point Graphs, this will recalculate all connections which passes through the bounds of the resulting Graph Update Object using raycasts (if enabled).