/rvo2-go

Primary LanguageGo

Optimal Reciprocal Collision Avoidance for Golang

New updates are released there. There are no explicit version numbers -- all commits on the master branch are supposed to be stable.

Latest Update: Simulation Monitor

  1. import Monitor
import (
	monitor "github.com/RuiHirano/rvo2-go/monitor"
)
  1. Create Monitor Instance
mo := monitor.NewMonitor(sim)
  1. Add Result of Each Step
mo.AddData(sim)
  1. Run Server
err := mo.RunServer()
if err != nil{
	fmt.Printf("error occor...: ", err)
}

You can watch simulation monitor at localhost:8000!

Building & installing

git clone https://github.com/RuiHirano/rvo2-go.git
cd rvo2-go/examples/simple
go build simple.go
./simple

Example code

package main

import (
	"fmt"
	"strconv"
	"math/rand"
	rvo "github.com/RuiHirano/rvo2-go/src/rvosimulator"
	monitor "github.com/RuiHirano/rvo2-go/monitor"
)

var (
	RAND_MAX int
)

func init() {
	RAND_MAX = 32767
}

func setupScenario(sim *rvo.RVOSimulator) {

	for i := 0; i < 5; i++ {
		for j := 0; j < 5; j++ {
			id, _ := sim.AddDefaultAgent(&rvo.Vector2{X: 3 + 0.1*rand.Float64(), Y: 0.8*rand.Float64()})
			sim.SetAgentPrefVelocity(id, &rvo.Vector2{X: 0+ 0.01*rand.Float64(), Y: -2 - 0.01*rand.Float64()})
			id, _ = sim.AddDefaultAgent(&rvo.Vector2{X: -5 + 0.1*rand.Float64(), Y: -0.8*rand.Float64()})
			sim.SetAgentPrefVelocity(id, &rvo.Vector2{X: 2+ 0.01*rand.Float64(), Y: 1 + 0.01*rand.Float64()})
			id, _ = sim.AddDefaultAgent(&rvo.Vector2{X: -2 + 0.1*rand.Float64(), Y: 5.5 + -0.8*rand.Float64()})
			sim.SetAgentPrefVelocity(id, &rvo.Vector2{X: 0+ 0.01*rand.Float64(), Y: -2 + 0.01*rand.Float64()})
			id, _ = sim.AddDefaultAgent(&rvo.Vector2{X: -2 + 0.1*rand.Float64(), Y: -5.5 + -0.8*rand.Float64()})
			sim.SetAgentPrefVelocity(id, &rvo.Vector2{X: 0+ 0.01*rand.Float64(), Y: 2 + 0.01*rand.Float64()})
			id, _ = sim.AddDefaultAgent(&rvo.Vector2{X: -2 + 0.1*rand.Float64(), Y: -5.5 + -0.8*rand.Float64()})
			sim.SetAgentPrefVelocity(id, &rvo.Vector2{X: 3+ 0.01*rand.Float64(), Y: -2 + 0.01*rand.Float64()})
		}
	}

	// Add (polygonal) obstacles, specifying their vertices in counterclockwise order
	obstacle1 := []*rvo.Vector2{
		&rvo.Vector2{X: -1, Y: 4.0},
		&rvo.Vector2{X: -4.0, Y: 4.0},
		&rvo.Vector2{X: -4.0, Y: 1},
		&rvo.Vector2{X: -1, Y: 1},
	}
	obstacle2 := []*rvo.Vector2{
		&rvo.Vector2{X: 1, Y: 4.0},
		&rvo.Vector2{X: 4.0, Y: 4.0},
		&rvo.Vector2{X: 4.0, Y: 1},
		&rvo.Vector2{X: 1, Y: 1},
	}
	obstacle3 := []*rvo.Vector2{
		&rvo.Vector2{X: -1, Y: -4.0},
		&rvo.Vector2{X: -1, Y: -1},
		&rvo.Vector2{X: -4.0, Y: -1},
		&rvo.Vector2{X: -4.0, Y: -4.0},
	}
	obstacle4 := []*rvo.Vector2{
		&rvo.Vector2{X: 1, Y: -4.0},
		&rvo.Vector2{X: 4.0, Y: -4.0},
		&rvo.Vector2{X: 4.0, Y: -1},
		&rvo.Vector2{X: 1, Y: -1},
	}

	// clockwise order: a wall is formed from inside to outside
	obstacle5 := []*rvo.Vector2{
		&rvo.Vector2{X: 6, Y: 6},
		&rvo.Vector2{X: 6, Y: -6},
		&rvo.Vector2{X: -6, Y: -6},
		&rvo.Vector2{X: -6, Y: 6},
	}
	sim.AddObstacle(obstacle1)
	sim.AddObstacle(obstacle2)
	sim.AddObstacle(obstacle3)
	sim.AddObstacle(obstacle4)
	sim.AddObstacle(obstacle5)
	sim.ProcessObstacles()

	fmt.Printf("Simulation has %v agents and %v obstacle vertices in it.\n", sim.GetNumAgents(), sim.GetNumObstacleVertices())
	fmt.Printf("Running Simulation...\n\n")
}

func showStatus(sim *rvo.RVOSimulator, step int){
	var agentPositions string
		agentPositions = ""
		for j := 0; j < sim.GetNumAgents(); j++ {
			agentPositions = agentPositions + " (" + strconv.FormatFloat(sim.GetAgentPosition(j).X, 'f', 3, 64) + "," + strconv.FormatFloat(sim.GetAgentPosition(j).Y, 'f', 4, 64) + ") "
		}
		fmt.Printf("step=%v  t=%v  %v \n", step+1, strconv.FormatFloat(sim.GlobalTime, 'f', 3, 64), agentPositions)

}

func main() {
	timeStep := 0.20
	neighborDist := 0.5
	maxneighbors := 20
	timeHorizon := 0.5
	timeHorizonObst := 0.5
	radius := 0.01
	maxSpeed := 0.5
	sim := rvo.NewRVOSimulator(timeStep, neighborDist, maxneighbors, timeHorizon, timeHorizonObst, radius, maxSpeed, &rvo.Vector2{X: 0, Y: 0})
	setupScenario(sim)
	// monitor
	mo := monitor.NewMonitor(sim)

	for step := 0; step < 34; step++ {

		sim.DoStep()
		showStatus(sim, step)

		// add data for monitor
		mo.AddData(sim)
	}
	// run monitor server
	err := mo.RunServer()
	if err != nil{
		fmt.Printf("error occor...: ", err)
	}
}

Attension!

Differences in befavior of obstacles

  1. If you specify obstacle vertices in counterclockwize order, wall is formed from inside to outside.

  2. If you specify obstacle vertices in clockwize order, wall is formed from outside to inside.

Parameter

Global Parameter

Paramater Type Description
GlobalTime float64 The Global Time of the simulation. Must be positive.
TimeStep float64 The time step of the simulation. Must be positive.

Agent Parameter

Paramater Type Description
MaxNeighbors int The maximal number of other agents the agent takes into account in the navigation. The larger this number, the longer the running time of the simulation. If the number is too low, the simulation will not be safe.
MaxSpeed float64 The maximum speed of the agent. Must be non-negative.
NeighborDist float64 The maximal distance (center point to center point) to other agents the agent takes into account in the navigation. The larger this number, the longer the running time of the simulation. If the number is too low, the simulation will not be safe. Must be non-negative.
Position *RVOSimulator.Vector2 The current position of the agent.
PrefVelocity float64 The current preferred velocity of the agent. This is the velocity the agent would take if no other agents or obstacles were around. The simulator computes an actual velocity for the agent that follows the preferred velocity as closely as possible, but at the same time guarantees collision avoidance.
Radius float64 The radius of the agent. Must be non-negative.
TimeHorizon float64 The minimal amount of time for which the agent's velocities that are computed by the simulation are safe with respect to other agents. The larger this number, the sooner this agent will respond to the presence of other agents, but the less freedom the agent has in choosing its velocities. Must be positive.
TimeHorizonObst float64 The minimal amount of time for which the agent's velocities that are computed by the simulation are safe with respect to obstacles. The larger this number, the sooner this agent will respond to the presence of obstacles, but the less freedom the agent has in choosing its velocities. Must be positive.
Velocity *RVOSimulator.Vector2 The (current) velocity of the agent.
Goal *RVOSimulator.Vector2 The Goal of the agent.

RVOSimulator Functions

Simulator Functions

Function Name Params Return Type Description
NewEmptyRVOSimulator None *RVOSimulator
NewRVOSimulator () *RVOSimulator
DoStep None None
SetTimeStep (timeStep float64 ) None
GetGlobalTime None float64
GetTimeStep None float64

Agent Functions

Function Name Params Return Type Description
AddDefaultAgent (position *RVOSimulator.Vector2) (id int, err bool)
AddAgent float64 (id int, err bool)
IsReachedGoal None bool
IsAgentReachedGoal (agentID int) bool
GetAgent (agentID int) *RVOSimulator.Agent
GetAgentPosition (agentID int) *RVOSimulator.Vector2
GetAgentPrefVelocity (agentID int) *RVOSimulator.Vector2
GetAgentRadius (agentID int) float64
GetAgentVelocity (agentID int) *RVOSimulator.Vector2
GetAgentNumAgents None int
GetAgentAgentNeighbor (agentID int, neighborID int) int
GetAgentMaxNeighbors (agentID int) int
GetAgentMaxSpeed (agentID int) float64
GetAgentNeighborDist (agentID int) float64
GetAgentNumAgentNeighbors (agentID int) int
GetAgentNumObstacleNeighbor (agentID int) int
GetAgentNumORCALines (agentID int) int
GetAgentTimeHorizon (agentID int) float64
GetAgentTimeHorizonObst (agentID int) float64
GetAgentORCALine (agentID int, lineNo int) *RVOSimulator.Line
GetAgentGoalVector (agentID int) *RVOSimulator.Vector2
SetAgentDefaults (neighborDist float64, maxNeighbors int, timeHorizon float64, timeHorizonObst float64, radius float64, maxSpeed float64, velocity *RVOSimulator.Vector2 ) None
SetAgentMaxNeighbors (agentID int, maxNeighbors int ) None
SetAgentMaxSpeed (agentID int, maxSpeed float64 ) None
SetAgentNeighborDist (agentID int, neighborDist float64 ) None
SetAgentPosition (agentID int, position *RVOSimulator.Vector2 ) None
SetAgentGoal (agentID int, goal *RVOSimulator.Vector2 ) None
SetAgentPrefVelocity (agentID int, velocity *RVOSimulator.Vector2 ) None
SetAgentVelocity (agentID int, velocity *RVOSimulator.Vector2 ) None
SetAgentRadius (agentID int, radius float64 ) None
SetAgentTimeHorizon (agentID int, timeHorizon float64 ) None
SetAgentTimeHorizonObst (agentID int, timeHorizonObst float64 ) None

Obstacle Functions

Function Name Params Return Type Description
AddObstacle (vertices []*RVOSimulator.Vector2) (id int, err bool)
ProcessObstacle None None

Optimal Reciprocal Collision Avoidance

http://gamma.cs.unc.edu/RVO2/

this library (rvo2-go) is based on rvo2-library (https://github.com/snape/RVO2).

Please send all bug reports about rvo2-go to issues of rvo2-go, and bug report for the RVO2 library itself to geom@cs.unc.edu.

The RVO2 authors may be contacted via:

Jur van den Berg, Stephen J. Guy, Jamie Snape, Ming C. Lin, and Dinesh Manocha
Dept. of Computer Science
201 S. Columbia St.
Frederick P. Brooks, Jr. Computer Science Bldg.
Chapel Hill, N.C. 27599-3175
United States of America