com.jme3.ai.agents.behaviours.npc.steering

Class ObstacleAvoidanceBehaviour

java.lang.Object

com.jme3.scene.control.AbstractControl

com.jme3.ai.agents.behaviours.Behaviour

com.jme3.ai.agents.behaviours.npc.steering.AbstractSteeringBehaviour

com.jme3.ai.agents.behaviours.npc.steering.AbstractStrengthSteeringBehaviour

com.jme3.ai.agents.behaviours.npc.steering.ObstacleAvoidanceBehaviour

All Implemented Interfaces:

com.jme3.export.Savable, com.jme3.scene.control.Control

Direct Known Subclasses:

UnalignedCollisionAvoidanceBehaviour

public class ObstacleAvoidanceBehaviour
extends AbstractStrengthSteeringBehaviour

Returns a steering force to avoid a given obstacle. The purely lateral steering force will turn our vehicle towards a silhouette edge of the obstacle. Avoidance is required when (1) the obstacle intersects the vehicle's current path, (2) it is in front of the vehicle, and (3) is within minTimeToCollision seconds of travel at the vehicle's current velocity. Returns a zero vector value when no avoidance is required.

The implementation of obstacle avoidance behavior here will make a simplifying assumption that both the character and obstacle can be reasonably approximated as spheres.

Keep in mind that this relates to obstacle avoidance not necessarily to collision detection.

The goal of the behavior is to keep an imaginary cylinder of free space in front of the character. The cylinder lies along the character's forward axis, has a diameter equal to the character's bounding sphere, and extends from the character's center for a distance based on the character's velocity.

It is needed that the obstacles (Agents) have the "radius" atribute correctly setted up.

Version:

1.1.1

Author:

Jesús Martín Berlanga

See Also:

Agent#setRadius(float)

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ObstacleAvoidanceBehaviour.ObstacleAvoindanceWithNegativeMinDistance
static class	ObstacleAvoidanceBehaviour.ObstacleAvoindanceWithNoMinTimeToCollision

Nested classes/interfaces inherited from class com.jme3.ai.agents.behaviours.npc.steering.AbstractStrengthSteeringBehaviour

AbstractStrengthSteeringBehaviour.negativeScalarMultiplier

Nested classes/interfaces inherited from class com.jme3.ai.agents.behaviours.npc.steering.AbstractSteeringBehaviour

AbstractSteeringBehaviour.IllegalBrakingFactor

Nested classes/interfaces inherited from class com.jme3.ai.agents.behaviours.Behaviour

Behaviour.behaviourNullAgentException

Field Summary

Fields inherited from class com.jme3.ai.agents.behaviours.npc.steering.AbstractSteeringBehaviour

velocity

Fields inherited from class com.jme3.ai.agents.behaviours.Behaviour

agent

Fields inherited from class com.jme3.scene.control.AbstractControl

enabled, spatial

Constructor Summary

Constructors

Constructor and Description
ObstacleAvoidanceBehaviour(Agent agent, java.util.List<Agent> obstacles, float minTimeToCollision)
ObstacleAvoidanceBehaviour(Agent agent, java.util.List<Agent> obstacles, float minTimeToCollision, float minDistance)
ObstacleAvoidanceBehaviour(Agent agent, java.util.List<Agent> obstacles, float minTimeToCollision, float minDistance, com.jme3.scene.Spatial spatial)
ObstacleAvoidanceBehaviour(Agent agent, java.util.List<Agent> obstacles, float minTimeToCollision, com.jme3.scene.Spatial spatial)

Method Summary

Methods

Modifier and Type	Method and Description
protected com.jme3.math.Vector3f	calculateFullSteering() If a bheaviour class extend from CompoundSteeringBehaviour instead of AbstractSteeringBehaviout, It must implement this method instead of calculateSteering().
protected void	controlRender(com.jme3.renderer.RenderManager rm, com.jme3.renderer.ViewPort vp)
protected float	getMinDistance()
protected float	getMinTimeToCollision()
protected java.util.List<Agent>	getObstacles()
protected com.jme3.math.Vector3f	randomVectInPlane(com.jme3.math.Vector3f planeNormalV, com.jme3.math.Vector3f planePoint)
void	setObstacles(java.util.List<Agent> obstacles)

Methods inherited from class com.jme3.ai.agents.behaviours.npc.steering.AbstractStrengthSteeringBehaviour

calculateSteering, setupStrengthControl, setupStrengthControl, setupStrengthControl, setupStrengthControl, turnOffStrengthControl

Methods inherited from class com.jme3.ai.agents.behaviours.npc.steering.AbstractSteeringBehaviour

agentTotalMass, calculateNewVelocity, controlUpdate, getBrakingFactor, getTPF, getVelocity, rotateAgent, setBrakingFactor, setTPF, setVelocity

Methods inherited from class com.jme3.scene.control.AbstractControl

cloneForSpatial, getSpatial, isEnabled, read, render, setEnabled, setSpatial, update, write

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ObstacleAvoidanceBehaviour

public ObstacleAvoidanceBehaviour(Agent agent,
                          java.util.List<Agent> obstacles,
                          float minTimeToCollision)

Parameters:

obstacles - A list with the obstacles (Agents)

minTimeToCollision - When the time to collision is lower than this value the steer force will appear. Time is measured in seconds.

Throws:

ObstacleAvoidanceBehaviour.ObstacleAvoindanceWithNoMinTimeToCollision - If minTimeToCollision is lower or equals to 0

See Also:

AbstractSteeringBehaviour.AbstractSteeringBehaviour(com.jme3.ai.agents.Agent)

ObstacleAvoidanceBehaviour

public ObstacleAvoidanceBehaviour(Agent agent,
                          java.util.List<Agent> obstacles,
                          float minTimeToCollision,
                          com.jme3.scene.Spatial spatial)

See Also:

ObstacleAvoidanceBehaviour(com.jme3.ai.agents.Agent, java.util.List, float), AbstractSteeringBehaviour.AbstractSteeringBehaviour(com.jme3.ai.agents.Agent, com.jme3.scene.Spatial)

ObstacleAvoidanceBehaviour

public ObstacleAvoidanceBehaviour(Agent agent,
                          java.util.List<Agent> obstacles,
                          float minTimeToCollision,
                          float minDistance)

Parameters:

minDistance - Min. distance from center to center to consider an obstacle

Throws:

ObstacleAvoidanceBehaviour.ObstacleAvoindanceWithNegativeMinDistance - If minTimeToCollision is lower than 0

See Also:

ObstacleAvoidanceBehaviour(com.jme3.ai.agents.Agent, java.util.List, float)

ObstacleAvoidanceBehaviour

public ObstacleAvoidanceBehaviour(Agent agent,
                          java.util.List<Agent> obstacles,
                          float minTimeToCollision,
                          float minDistance,
                          com.jme3.scene.Spatial spatial)

See Also:

ObstacleAvoidanceBehaviour#ObstacleAvoidanceBehaviour(com.jme3.ai.agents.Agent, com.jme3.scene.Spatial, java.util.List, float), AbstractSteeringBehaviour.AbstractSteeringBehaviour(com.jme3.ai.agents.Agent, com.jme3.scene.Spatial)

Method Detail

getObstacles

protected java.util.List<Agent> getObstacles()

setObstacles

public void setObstacles(java.util.List<Agent> obstacles)

getMinTimeToCollision

protected float getMinTimeToCollision()

getMinDistance

protected float getMinDistance()

calculateFullSteering

protected com.jme3.math.Vector3f calculateFullSteering()

Description copied from class: AbstractStrengthSteeringBehaviour

If a bheaviour class extend from CompoundSteeringBehaviour instead of AbstractSteeringBehaviout, It must implement this method instead of calculateSteering().

Specified by:

calculateFullSteering in class AbstractStrengthSteeringBehaviour

See Also:

AbstractSteeringBehaviour.calculateSteering()

controlRender

protected void controlRender(com.jme3.renderer.RenderManager rm,
                 com.jme3.renderer.ViewPort vp)

Specified by:

controlRender in class com.jme3.scene.control.AbstractControl

randomVectInPlane

protected com.jme3.math.Vector3f randomVectInPlane(com.jme3.math.Vector3f planeNormalV,
                                       com.jme3.math.Vector3f planePoint)