Simulator Class Reference

Local Avoidance Simulator. More...

Collaboration diagram for Simulator:

Classes
class	Worker

Public Member Functions
	Simulator (int workers, bool doubleBuffering)
	Create a new simulator.
IAgent	AddAgent (IAgent agent)
	Add a previously removed agent to the simulation.
IAgent	AddAgent (Vector3 position)
	Add an agent at the specified position.
ObstacleVertex	AddObstacle (ObstacleVertex v)
	Adds a previously removed obstacle.
ObstacleVertex	AddObstacle (Vector3[] vertices, float height)
	Adds an obstacle described by the vertices.
ObstacleVertex	AddObstacle (Vector3[] vertices, float height, Matrix4x4 matrix)
	Adds an obstacle described by the vertices.
ObstacleVertex	AddObstacle (Vector3 a, Vector3 b, float height)
	Adds a line obstacle with a specified height.
void	ClearAgents ()
	Removes all agents from the simulation.
List< Agent >	GetAgents ()
	Get a list of all agents.
List< ObstacleVertex >	GetObstacles ()
	Get a list of all obstacles.
void	RemoveAgent (IAgent agent)
	Removes a specified agent from this simulation.
void	RemoveObstacle (ObstacleVertex v)
	Removes the obstacle identified by the vertex.
void	Update ()
	Should be called once per frame.
void	UpdateObstacle (ObstacleVertex obstacle, Vector3[] vertices, Matrix4x4 matrix)
	Updates the vertices of an obstacle.
void	UpdateObstacles ()
	Rebuilds the obstacle tree at next simulation frame.

Properties
float	DeltaTime [get]
float	DesiredDeltaTime [get, set]
	Time in seconds between each simulation step.
float	FrameDeltaTime [get]
bool	Interpolation [get, set]
	Use Interpolation.
KDTree	KDTree [get]
	KDTree for this simulation.
bool	Multithreading [get]
	Is using multithreading.
float	PrevDeltaTime [get]

Private Member Functions
	~Simulator ()
	Terminates any worker threads.
void	CleanObstacles ()
void	ScheduleCleanObstacles ()

Private Attributes
List< Agent >	agents
	Agents in this simulation.
float	deltaTime
float	desiredDeltaTime = 0.05f
	Inverse desired simulation fps.
bool	doCleanObstacles = false
bool	doubleBuffering = true
	Use Double Buffering.
bool	doUpdateObstacles = false
float	frameDeltaTime
float[]	frameTimeBuffer = new float[5]
int	frameTimeBufferIndex = 0
bool	interpolation = true
	Use Interpolation.
KDTree	kdTree
	KDTree for this simulation.
float	lastFrame = 0
float	lastStep = -99999
List< ObstacleVertex >	obstacles
	Obstacles in this simulation.
float	prevDeltaTime = 0
Worker[]	workers
	Worker threads.

Detailed Description

Local Avoidance Simulator.

This class handles local avoidance simulation for a number of agents using Reciprocal Velocity Obstacles (RVO) and Optimal Reciprocal Collision Avoidance (ORCA).

This class will handle calculation of velocities from desired velocities supplied by a script. It is, however, not responsible for moving any objects in a Unity Scene. For that there are other scripts (see below).

Obstacles can be added and removed from the simulation, agents can also be added and removed at any time.

See Also

RVOSimulator RVOAgent Pathfinding.RVO.IAgent

The implementation is based on the RVO2 Library (http://gamma.cs.unc.edu/RVO2/) extended with many new features.

Constructor & Destructor Documentation

Simulator	(	int	workers,
		bool	doubleBuffering
	)

Create a new simulator.

Parameters

workers	Use the specified number of worker threads. When the number zero is specified, no multithreading will be used. A good number is the number of cores on the machine.
doubleBuffering	Use Double Buffering for calculations. Testing done with 5000 agents and 0.1 desired delta time showed that with double buffering enabled the game ran at 50 fps for most frames, dropping to 10 fps during calculation frames. But without double buffering it ran at around 10 fps all the time. This will let threads calculate while the game progresses instead of waiting for the calculations to finish.

Note

Will only have effect if using multithreading

See Also

Multithreading

Member Function Documentation

IAgent AddAgent

(

IAgent

agent

)

Add a previously removed agent to the simulation.

An agent can only be in one simulation at a time, any attempt to add an agent to two simulations or multiple times to the same simulation will result in an exception being thrown.

See Also

RemoveAgent

Here is the caller graph for this function:

IAgent AddAgent

(

Vector3

position

)

Add an agent at the specified position.

You can use the returned interface to read several parameters such as position and velocity and set for example radius and desired velocity.

See Also

RemoveAgent

ObstacleVertex AddObstacle

(

ObstacleVertex

v

)

Adds a previously removed obstacle.

This does not check if the obstacle is already added to the simulation, so please do not add an obstacle multiple times.

It is assumed that this is a valid obstacle.

Here is the caller graph for this function:

ObstacleVertex AddObstacle	(	Vector3[]	vertices,
		float	height
	)

Adds an obstacle described by the vertices.

See Also

RemoveObstacle

ObstacleVertex AddObstacle	(	Vector3[]	vertices,
		float	height,
		Matrix4x4	matrix
	)

Adds an obstacle described by the vertices.

See Also

RemoveObstacle

Here is the call graph for this function:

ObstacleVertex AddObstacle	(	Vector3	a,
		Vector3	b,
		float	height
	)

Adds a line obstacle with a specified height.

See Also

RemoveObstacle

List<Agent> GetAgents

(

)

Get a list of all agents.

This is an internal list. I'm not going to be restrictive so you may access it since it is better for performance but please do not modify it since that can cause errors in the simulation.

Warning

Do not modify this list!

List<ObstacleVertex> GetObstacles

(

)

Get a list of all obstacles.

This is a list of obstacle vertices. Each vertex is part of a doubly linked list loop forming an obstacle polygon.

Warning

Do not modify this list!

See Also

AddObstacle

RemoveObstacle

void RemoveAgent

(

IAgent

agent

)

Removes a specified agent from this simulation.

The agent can be added again later by using AddAgent.

See Also

AddAgent(IAgent)

ClearAgents

void RemoveObstacle

(

ObstacleVertex

v

)

Removes the obstacle identified by the vertex.

This must be the same vertex as the one returned by the AddObstacle call.

See Also

AddObstacle

Here is the caller graph for this function:

void UpdateObstacle	(	ObstacleVertex	obstacle,
		Vector3[]	vertices,
		Matrix4x4	matrix
	)

Updates the vertices of an obstacle.

Parameters

obstacle	Obstacle to update
vertices	New vertices for the obstacle, must have at least the number of vertices in the original obstacle
matrix	Matrix to multiply vertices with before updating obstacle

The number of vertices in an obstacle cannot be changed, existing vertices can only be moved.

Here is the call graph for this function:

Here is the caller graph for this function:

void UpdateObstacles

(

)

Rebuilds the obstacle tree at next simulation frame.

Add and remove obstacle functions call this automatically.

Member Data Documentation

float desiredDeltaTime = 0.05f

private

Inverse desired simulation fps.

See Also

DesiredDeltaTime

bool doubleBuffering = true

private

Use Double Buffering.

See Also

DoubleBuffering

bool interpolation = true

private

Use Interpolation.

See Also

Interpolation

Property Documentation

float DesiredDeltaTime

getset

Time in seconds between each simulation step.

This is the desired delta time, the simulation will never run at a higher fps than the rate at which the Update function is called.

bool Interpolation

getset

Use Interpolation.

If interpolation is enabled, agent positions will be interpolated on frames when no rvo calculation is done. This has a very small overhead, but usually yields much smoother looking movement.

KDTree KDTree

get

KDTree for this simulation.

Used internally by the simulation. Please only read from this tree, do not rebuild it since that can interfere with the simulation. It is rebuilt when needed.

---

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

• /Users/aron/Unity/AstarPathfindingGIT/Assets/AstarPathfindingProject/Core/RVO/RVOCoreSimulator.cs