Agent.VO Struct Reference

Velocity Obstacle. More...

Detailed Description

Velocity Obstacle.

This is a struct to avoid too many allocations.

See also

https://en.wikipedia.org/wiki/Velocity_obstacle

Public Member Functions
	VO (Vector2 center, Vector2 offset, float radius, float inverseDt, float inverseDeltaTime)
	Creates a VO for avoiding another agent. More...
Vector2	Gradient (Vector2 p, out float weight)
	Gradient and value of the cost function of this VO. More...
Vector2	ScaledGradient (Vector2 p, out float weight)
	Gradient and value of the cost function of this VO. More...

Static Public Member Functions
static VO	SegmentObstacle (Vector2 segmentStart, Vector2 segmentEnd, Vector2 offset, float radius, float inverseDt, float inverseDeltaTime)
	Creates a VO for avoiding another agent. More...
static float	SignedDistanceFromLine (Vector2 a, Vector2 dir, Vector2 p)
	Returns a negative number of if p lies on the left side of a line which with one point in a and has a tangent in the direction of dir. More...

Public Attributes
Vector2	circleCenter
bool	colliding
Vector2	cutoffDir
Vector2	cutoffLine
Vector2	dir1
Vector2	dir2
Vector2	line1
Vector2	line2
float	radius
bool	segment
Vector2	segmentEnd
Vector2	segmentStart
float	weightBonus
float	weightFactor

Constructor & Destructor Documentation

VO()

VO	(	Vector2	center,
		Vector2	offset,
		float	radius,
		float	inverseDt,
		float	inverseDeltaTime
	)

Creates a VO for avoiding another agent.

Parameters

center	The position of the other agent relative to this agent.
offset	Offset of the velocity obstacle. For example to account for the agents' relative velocities.
radius	Combined radius of the two agents (radius1 + radius2).
inverseDt	1 divided by the local avoidance time horizon (e.g avoid agents that we will hit within the next 2 seconds).
inverseDeltaTime	1 divided by the time step length.

Member Function Documentation

Gradient()

Vector2 Gradient	(	Vector2	p,
		out float	weight
	)

Gradient and value of the cost function of this VO.

The VO has a cost function which is 0 outside the VO and increases inside it as the point moves further into the VO.

This is the negative gradient of that function as well as its value (the weight). The negative gradient points in the direction where the function decreases the fastest.

The value of the function is the distance to the closest edge of the VO and the gradient is normalized.

ScaledGradient()

Vector2 ScaledGradient	(	Vector2	p,
		out float	weight
	)

Gradient and value of the cost function of this VO.

Very similar to the Gradient method however the gradient and value have been scaled and tweaked slightly.

SegmentObstacle()

static VO SegmentObstacle ( Vector2  segmentStart, Vector2  segmentEnd, Vector2  offset, float  radius, float  inverseDt, float  inverseDeltaTime  )

static

Creates a VO for avoiding another agent.

Note that the segment is directed, the agent will want to be on the left side of the segment.

SignedDistanceFromLine()

static float SignedDistanceFromLine ( Vector2  a, Vector2  dir, Vector2  p  )

static

Returns a negative number of if p lies on the left side of a line which with one point in a and has a tangent in the direction of dir.

The number can be seen as the double signed area of the triangle {a, a+dir, p} multiplied by the length of dir. If dir.magnitude=1 this is also the distance from p to the line {a, a+dir}.

Member Data Documentation

circleCenter

Vector2 circleCenter

colliding

bool colliding

cutoffDir

Vector2 cutoffDir

cutoffLine

Vector2 cutoffLine

dir1

Vector2 dir1

dir2

Vector2 dir2

line1

Vector2 line1

line2

Vector2 line2

radius

float radius

segment

bool segment

segmentEnd

Vector2 segmentEnd

segmentStart

Vector2 segmentStart

weightBonus

float weightBonus

weightFactor

float weightFactor

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

• /Users/arong/Unity/a-pathfinding-project/Assets/AstarPathfindingProject/Core/RVO/RVOAgent.cs