Linearly interpolating movement script. More...

Detailed Description

Linearly interpolating movement script.

This movement script will follow the path exactly, it uses linear interpolation to move between the waypoints in the path. This is desirable for some types of games. It also works in 2D.

See also: You can see an example of this script in action in the example scene called Example15_2D.

Configuration

Recommended setup for movement along connections

This depends on what type of movement you are aiming for. If you are aiming for movement where the unit follows the path exactly and move only along the graph connections on a grid/point graph. I recommend that you adjust the StartEndModifier on the Seeker component: set the 'Start Point Snapping' field to 'NodeConnection' and the 'End Point Snapping' field to 'SnapToNode'.

Recommended setup for smooth movement

If you on the other hand want smoother movement I recommend setting 'Start Point Snapping' and 'End Point Snapping' to 'ClosestOnNode' and to add the Simple Smooth Modifier to the GameObject as well. Alternatively you can use the Funnel Modifier which works better on navmesh/recast graphs or the RaycastModifier.

You should not combine the Simple Smooth Modifier or the Funnel Modifier with the NodeConnection snapping mode. This may lead to very odd behavior.

You may also want to tweak the rotationSpeed.

Public Member Functions
void	FinalizeMovement (Vector3 nextPosition, Quaternion nextRotation)
	Move the agent. More...

virtual void	ForceSearchPath ()
	Requests a path to the target. More...

virtual Vector3	GetFeetPosition ()

void	MovementUpdate (float deltaTime, out Vector3 nextPosition, out Quaternion nextRotation)
	Calculate how the character wants to move during this frame. More...

void	OnDisable ()

virtual void	OnTargetReached ()
	The end of the path has been reached. More...

virtual void	SearchPath ()
	Requests a path to the target. More...

void	SetPath (Path path)
	Make the AI follow the specified path. More...

void	Teleport (Vector3 position, bool clearPath=true)
	Instantly move the agent to a new position. More...

Public Attributes
bool	canMove = true
	Enables or disables movement completely. More...

bool	canSearch = true
	Enables or disables recalculating the path at regular intervals. More...

bool	enableRotation = true
	If true, the AI will rotate to face the movement direction. More...

bool	interpolatePathSwitches = true
	If true, some interpolation will be done when a new path has been calculated. More...

float	repathRate = 0.5F
	Determines how often it will search for new paths. More...

bool	rotationIn2D = false
	If true, rotation will only be done along the Z axis so that the Y axis is the forward direction of the character. More...

float	rotationSpeed = 10
	How quickly to rotate. More...

float	speed = 3
	Speed in world units. More...

float	switchPathInterpolationSpeed = 5
	How quickly to interpolate to the new path. More...

bool	updatePosition = true
	Determines if the character's position should be coupled to the Transform's position. More...

bool	updateRotation = true
	Determines if the character's rotation should be coupled to the Transform's rotation. More...

Protected Member Functions
override void	Awake ()
	Initializes reference variables. More...

virtual Vector3	CalculateNextPosition (out Vector3 direction, float deltaTime)
	Calculate the AI's next position (one frame in the future). More...

virtual void	ConfigureNewPath ()
	Finds the closest point on the current path and configures the interpolator. More...

virtual void	ConfigurePathSwitchInterpolation ()

virtual void	OnEnable ()
	Called when the component is enabled. More...

virtual void	OnPathComplete (Path _p)
	Called when a requested path has finished calculation. More...

override int	OnUpgradeSerializedData (int version, bool unityThread)
	Handle serialization backwards compatibility. More...

virtual void	Start ()
	Starts searching for paths. More...

virtual void	Update ()

Protected Attributes
bool	canSearchAgain = true
	Only when the previous path has been returned should a search for a new path be done. More...

PathInterpolator	interpolator = new PathInterpolator()

float	lastRepath = -9999
	Time when the last path request was sent. More...

ABPath	path
	Current path which is followed. More...

float	pathSwitchInterpolationTime = 0
	Time since the path was replaced by a new path. More...

Vector3	previousMovementDirection

Vector3	previousMovementOrigin
	When a new path was returned, the AI was moving along this ray. More...

Seeker	seeker
	Cached Seeker component. More...

Transform	tr
	Cached Transform component. More...

Properties
bool IAstarAI.	canMove `[get, set]`
	Enables or disables movement completely. More...

bool IAstarAI.	canSearch `[get, set]`
	Enables or disables recalculating the path at regular intervals. More...

Vector3 IAstarAI.	desiredVelocity `[get]`

Vector3	destination `[get, set]`

bool	hasPath `[get]`

bool	isStopped `[get, set]`
	Gets or sets if the agent should stop moving. More...

float IAstarAI.	maxSpeed `[get, set]`
	Max speed in world units per second. More...

System.Action	onSearchPath `[get, set]`
	Called when the agent recalculates its path. More...

bool	pathPending `[get]`

Vector3	position `[get]`
	Position of the agent. More...

bool	reachedEndOfPath `[get, private set]`
	True if the end of the current path has been reached. More...

float	remainingDistance `[get, set]`

Quaternion	rotation `[get]`
	Rotation of the agent. More...

virtual bool	shouldRecalculatePath `[get]`
	True if the path should be automatically recalculated as soon as possible. More...

Vector3 IAstarAI.	steeringTarget `[get]`
	Point on the path which the agent is currently moving towards. More...

Transform	target `[get, set]`
	Target to move towards. More...

Vector3 IAstarAI.	velocity `[get]`

Properties inherited from IAstarAI
bool	canMove `[get, set]`
	Enables or disables movement completely. More...

bool	canSearch `[get, set]`
	Enables or disables recalculating the path at regular intervals. More...

Vector3	desiredVelocity `[get]`
	Velocity that this agent wants to move with. More...

Vector3	destination `[get, set]`
	Position in the world that this agent should move to. More...

bool	hasPath `[get]`
	True if this agent currently has a path that it follows. More...

bool	isStopped `[get, set]`
	Gets or sets if the agent should stop moving. More...

float	maxSpeed `[get, set]`
	Max speed in world units per second. More...

System.Action	onSearchPath `[get, set]`
	Called when the agent recalculates its path. More...

bool	pathPending `[get]`
	True if a path is currently being calculated. More...

Vector3	position `[get]`
	Position of the agent. More...

bool	reachedEndOfPath `[get]`
	True if the agent has reached the end of the current path. More...

float	remainingDistance `[get]`
	Remaining distance along the current path to the end of the path. More...

Quaternion	rotation `[get]`
	Rotation of the agent. More...

Vector3	steeringTarget `[get]`
	Point on the path which the agent is currently moving towards. More...

Vector3	velocity `[get]`
	Actual velocity that the agent is moving with. More...

Private Member Functions
void	Init ()

void IAstarAI.	Move (Vector3 deltaPosition)
	Move the agent. More...

Quaternion	SimulateRotationTowards (Vector3 direction, float deltaTime)

Private Attributes
Vector3	previousPosition1

Vector3	previousPosition2

Vector3	simulatedPosition

Quaternion	simulatedRotation

bool	startHasRun = false
	Holds if the Start function has been run. More...

Transform	targetCompatibility
	Required for serialization backward compatibility. More...

Member Function Documentation

◆ Awake()

override void Awake ( )

protectedvirtual

Initializes reference variables.

If you override this function you should in most cases call base.Awake () at the start of it.

Reimplemented from VersionedMonoBehaviour.

◆ CalculateNextPosition()

virtual Vector3 CalculateNextPosition	(	out Vector3	direction,
		float	deltaTime
	)

protectedvirtual

Calculate the AI's next position (one frame in the future).

Parameters

direction The tangent of the segment the AI is currently traversing. Not normalized.

◆ ConfigureNewPath()

virtual void ConfigureNewPath ( )

protectedvirtual

Finds the closest point on the current path and configures the interpolator.

◆ ConfigurePathSwitchInterpolation()

virtual void ConfigurePathSwitchInterpolation ( )

protectedvirtual

◆ FinalizeMovement()

void FinalizeMovement	(	Vector3	nextPosition,
		Quaternion	nextRotation
	)

Move the agent.

To be called as the last step when you are handling movement manually.

The movement will be clamped to the navmesh if applicable (this is done for the RichAI movement script).

See also: MovementUpdate for a code example.

Implements IAstarAI.

◆ ForceSearchPath()

virtual void ForceSearchPath ( )

virtual

Requests a path to the target.

Deprecated:: Use SearchPath instead.

◆ GetFeetPosition()

virtual Vector3 GetFeetPosition ( )

virtual

◆ Init()

void Init ( )

private

◆ Move()

void IAstarAI. Move ( Vector3 deltaPosition )

private

Move the agent.

Parameters

deltaPosition Direction and distance to move the agent in world space.

This is intended for external movement forces such as those applied by wind, conveyor belts, knockbacks etc.

Some movement scripts may ignore this completely (notably the AILerp script) if it does not have any concept of being moved externally.

The agent will not be moved immediately when calling this method. Instead this offset will be stored and then applied the next time the agent runs its movement calculations (which is usually later this frame or the next frame). If you want to move the agent immediately then call:

ai.Move(someVector);

ai.FinalizeMovement(ai.position, ai.rotation);

Implements IAstarAI.

◆ MovementUpdate()

void MovementUpdate	(	float	deltaTime,
		out Vector3	nextPosition,
		out Quaternion	nextRotation
	)

Calculate how the character wants to move during this frame.

Parameters

deltaTime	time to simulate movement for. Usually set to Time.deltaTime.
nextPosition	the position that the agent wants to move to during this frame.
nextRotation	the rotation that the agent wants to rotate to during this frame.

Note that this does not actually move the character. You need to call FinalizeMovement for that. This is called automatically unless canMove is false.

To handle movement yourself you can disable canMove and call this method manually. This code will replicate the normal behavior of the component:

    void Update () {
        // Disable the AIs own movement code
        ai.canMove = false;
        Vector3 nextPosition;
        Quaternion nextRotation;
        // Calculate how the AI wants to move
        ai.MovementUpdate(Time.deltaTime, out nextPosition, out nextRotation);
        // Modify nextPosition and nextRotation in any way you wish
        // Actually move the AI
        ai.FinalizeMovement(nextPosition, nextRotation);
    }

Implements IAstarAI.

◆ OnDisable()

void OnDisable ( )

◆ OnEnable()

virtual void OnEnable ( )

protectedvirtual

Called when the component is enabled.

◆ OnPathComplete()

virtual void OnPathComplete ( Path _p )

protectedvirtual

Called when a requested path has finished calculation.

A path is first requested by SearchPath, it is then calculated, probably in the same or the next frame. Finally it is returned to the seeker which forwards it to this function.

◆ OnTargetReached()

virtual void OnTargetReached ( )

virtual

The end of the path has been reached.

If you want custom logic for when the AI has reached it's destination add it here. You can also create a new script which inherits from this one and override the function in that script.

◆ OnUpgradeSerializedData()

override int OnUpgradeSerializedData	(	int	version,
		bool	unityThread
	)

protectedvirtual

Handle serialization backwards compatibility.

Reimplemented from VersionedMonoBehaviour.

◆ SearchPath()

virtual void SearchPath ( )

virtual

Requests a path to the target.

Implements IAstarAI.

◆ SetPath()

void SetPath ( Path path )

Make the AI follow the specified path.

In case the path has not been calculated, the script will call seeker.StartPath to calculate it. This means the AI may not actually start to follow the path until in a few frames when the path has been calculated. The pathPending field will as usual return true while the path is being calculated.

In case the path has already been calculated it will immediately replace the current path the AI is following. This is useful if you want to replace how the AI calculates its paths. Note that if you calculate the path using seeker.StartPath then this script will already pick it up because it is listening for all paths that the Seeker finishes calculating. In that case you do not need to call this function.

You can disable the automatic path recalculation by setting the canSearch field to false.

        // Disable the automatic path recalculation
        ai.canSearch = false;
        var pointToAvoid = enemy.position;
        // Make the AI flee from the enemy.
        // The path will be about 20 world units long (the default cost of moving 1 world unit is 1000).
        var path = FleePath.Construct(ai.position, pointToAvoid, 1000 * 20);
        ai.SetPath(path);

Implements IAstarAI.

◆ SimulateRotationTowards()

Quaternion SimulateRotationTowards	(	Vector3	direction,
		float	deltaTime
	)

private

◆ Start()

virtual void Start ( )

protectedvirtual

Starts searching for paths.

If you override this function you should in most cases call base.Start () at the start of it.

See also: Init; #RepeatTrySearchPath

◆ Teleport()

void Teleport	(	Vector3	newPosition,
		bool	clearPath = `true`
	)

Instantly move the agent to a new position.

This will trigger a path recalculation (if clearPath is true, which is the default) so if you want to teleport the agent and change its destination it is recommended that you set the destination before calling this method.

The current path will be cleared by default.

See also: Works similarly to Unity's NavmeshAgent.Warp.; SearchPath

Implements IAstarAI.

◆ Update()

virtual void Update ( )

protectedvirtual

Member Data Documentation

◆ canMove

bool canMove = true

Enables or disables movement completely.

If you want the agent to stand still, but still react to local avoidance and use gravity: use isStopped instead.

This is also useful if you want to have full control over when the movement calculations run. Take a look at MovementUpdate

See also: canSearch; isStopped

◆ canSearch

bool canSearch = true

Enables or disables recalculating the path at regular intervals.

Setting this to false does not stop any active path requests from being calculated or stop it from continuing to follow the current path.

Note that this only disables automatic path recalculations. If you call the SearchPath() method a path will still be calculated.

See also: canMove; isStopped

◆ canSearchAgain

bool canSearchAgain = true

protected

Only when the previous path has been returned should a search for a new path be done.

◆ enableRotation

bool enableRotation = true

If true, the AI will rotate to face the movement direction.

◆ interpolatePathSwitches

bool interpolatePathSwitches = true

If true, some interpolation will be done when a new path has been calculated.

This is used to avoid short distance teleportation.

◆ interpolator

PathInterpolator interpolator = new PathInterpolator()

protected

◆ lastRepath

float lastRepath = -9999

protected

Time when the last path request was sent.

◆ path

ABPath path

protected

Current path which is followed.

◆ pathSwitchInterpolationTime

float pathSwitchInterpolationTime = 0

protected

Time since the path was replaced by a new path.

See also: interpolatePathSwitches

◆ previousMovementDirection

Vector3 previousMovementDirection

protected

◆ previousMovementOrigin

Vector3 previousMovementOrigin

protected

When a new path was returned, the AI was moving along this ray.

Used to smoothly interpolate between the previous movement and the movement along the new path. The speed is equal to movement direction.

◆ previousPosition1

Vector3 previousPosition1

private

◆ previousPosition2

Vector3 previousPosition2

private

◆ repathRate

float repathRate = 0.5F

Determines how often it will search for new paths.

If you have fast moving targets or AIs, you might want to set it to a lower value. The value is in seconds between path requests.

◆ rotationIn2D

bool rotationIn2D = false

If true, rotation will only be done along the Z axis so that the Y axis is the forward direction of the character.

This is useful for 2D games in which one often want to have the Y axis as the forward direction to get sprites and 2D colliders to work properly.

◆ rotationSpeed

float rotationSpeed = 10

How quickly to rotate.

◆ seeker

Seeker seeker

protected

Cached Seeker component.

◆ simulatedPosition

Vector3 simulatedPosition

private

◆ simulatedRotation

Quaternion simulatedRotation

private

◆ speed

float speed = 3

Speed in world units.

◆ startHasRun

bool startHasRun = false

private

Holds if the Start function has been run.

Used to test if coroutines should be started in OnEnable to prevent calculating paths in the awake stage (or rather before start on frame 0).

◆ switchPathInterpolationSpeed

float switchPathInterpolationSpeed = 5

How quickly to interpolate to the new path.

◆ targetCompatibility

Transform targetCompatibility

private

Required for serialization backward compatibility.

◆ tr

Transform tr

protected

Cached Transform component.

◆ updatePosition

bool updatePosition = true

Determines if the character's position should be coupled to the Transform's position.

If false then all movement calculations will happen as usual, but the object that this component is attached to will not move instead only the position property will change.

See also: canMove which in contrast to this field will disable all movement calculations.; updateRotation

◆ updateRotation

bool updateRotation = true

Determines if the character's rotation should be coupled to the Transform's rotation.

If false then all movement calculations will happen as usual, but the object that this component is attached to will not rotate instead only the rotation property will change.

See also: updatePosition

Property Documentation

◆ canMove

bool IAstarAI. canMove

getsetprivate

Enables or disables movement completely.

If you want the agent to stand still, but still react to local avoidance and use gravity: use isStopped instead.

This is also useful if you want to have full control over when the movement calculations run. Take a look at MovementUpdate

See also: canSearch; isStopped

◆ canSearch

bool IAstarAI. canSearch

getsetprivate

Enables or disables recalculating the path at regular intervals.

Setting this to false does not stop any active path requests from being calculated or stop it from continuing to follow the current path.

Note that this only disables automatic path recalculations. If you call the SearchPath() method a path will still be calculated.

See also: canMove; isStopped

◆ desiredVelocity

Vector3 IAstarAI. desiredVelocity

getprivate

◆ destination

Vector3 destination

getset

◆ hasPath

bool hasPath

get

◆ isStopped

bool isStopped

getset

Gets or sets if the agent should stop moving.

If this is set to true the agent will immediately start to slow down as quickly as it can to come to a full stop. The agent will still react to local avoidance and gravity (if applicable), but it will not try to move in any particular direction.

The current path of the agent will not be cleared, so when this is set to false again the agent will continue moving along the previous path.

This is a purely user-controlled parameter, so for example it is not set automatically when the agent stops moving because it has reached the target. Use reachedEndOfPath for that.

If this property is set to true while the agent is traversing an off-mesh link (RichAI script only), then the agent will continue traversing the link and stop once it has completed it.

Note: This is not the same as the canMove setting which some movement scripts have. The canMove setting disables movement calculations completely (which among other things makes it not be affected by local avoidance or gravity). For the AILerp movement script which doesn't use gravity or local avoidance anyway changing this property is very similar to changing canMove.

The steeringTarget property will continue to indicate the point which the agent would move towards if it would not be stopped.

◆ maxSpeed

float IAstarAI. maxSpeed

getsetprivate

Max speed in world units per second.

◆ onSearchPath

System.Action onSearchPath

getset

Called when the agent recalculates its path.

This is called both for automatic path recalculations (see canSearch) and manual ones (see SearchPath).

See also: Take a look at the Pathfinding.AIDestinationSetter source code for an example of how it can be used.

◆ pathPending

bool pathPending

get

◆ position

Vector3 position

get

Position of the agent.

In world space.

See also: rotation

◆ reachedEndOfPath

bool reachedEndOfPath

getprivate set

True if the end of the current path has been reached.

◆ remainingDistance

float remainingDistance

getset

◆ rotation

Quaternion rotation

get

Rotation of the agent.

In world space.

See also: position

◆ shouldRecalculatePath

virtual bool shouldRecalculatePath

getprotected

True if the path should be automatically recalculated as soon as possible.

◆ steeringTarget

Vector3 IAstarAI. steeringTarget

getprivate

Point on the path which the agent is currently moving towards.

This is usually a point a small distance ahead of the agent or the end of the path.

If the agent does not have a path at the moment, then the agent's current position will be returned.

◆ target

Transform target

getset

Target to move towards.

The AI will try to follow/move towards this target. It can be a point on the ground where the player has clicked in an RTS for example, or it can be the player object in a zombie game.

Deprecated:: In 4.0 this will automatically add a AIDestinationSetter component and set the target on that component. Try instead to use the destination property which does not require a transform to be created as the target or use the AIDestinationSetter component directly.

◆ velocity

Vector3 IAstarAI. velocity

getprivate

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

/Users/arong/Unity/a-pathfinding-project/Assets/AstarPathfindingProject/Core/AI/AILerp.cs

Detailed Description

Configuration

Recommended setup for movement along connections

Recommended setup for smooth movement

Public Member Functions

Public Attributes

Protected Member Functions

Protected Attributes

Properties

Private Member Functions

Private Attributes

Member Function Documentation

◆ Awake()

◆ CalculateNextPosition()

◆ ConfigureNewPath()

◆ ConfigurePathSwitchInterpolation()

◆ FinalizeMovement()

◆ ForceSearchPath()

◆ GetFeetPosition()

◆ Init()

◆ Move()

◆ MovementUpdate()

◆ OnDisable()

◆ OnEnable()

◆ OnPathComplete()

◆ OnTargetReached()

◆ OnUpgradeSerializedData()

◆ SearchPath()

◆ SetPath()

◆ SimulateRotationTowards()

◆ Start()

◆ Teleport()

◆ Update()

Member Data Documentation

◆ canMove

◆ canSearch

◆ canSearchAgain

◆ enableRotation

◆ interpolatePathSwitches

◆ interpolator

◆ lastRepath

◆ path

◆ pathSwitchInterpolationTime

◆ previousMovementDirection

◆ previousMovementOrigin

◆ previousPosition1

◆ previousPosition2

◆ repathRate

◆ rotationIn2D

◆ rotationSpeed

◆ seeker

◆ simulatedPosition

◆ simulatedRotation

◆ speed

◆ startHasRun

◆ switchPathInterpolationSpeed

◆ targetCompatibility

◆ tr

◆ updatePosition

◆ updateRotation

Property Documentation

◆ canMove

◆ canSearch

◆ desiredVelocity

◆ destination

◆ hasPath

◆ isStopped

◆ maxSpeed

◆ onSearchPath

◆ pathPending

◆ position

◆ reachedEndOfPath

◆ remainingDistance

◆ rotation

◆ shouldRecalculatePath

◆ steeringTarget

◆ target

◆ velocity