javax.media.j3d

Class DistanceLOD

java.lang.Object

javax.media.j3d.SceneGraphObject

javax.media.j3d.Node

javax.media.j3d.Leaf

javax.media.j3d.Behavior

javax.media.j3d.LOD

javax.media.j3d.DistanceLOD

public class DistanceLOD
extends LOD

This class defines a distance-based LOD behavior node that operates on a Switch group node to select one of the children of that Switch node based on the distance of this LOD node from the viewer. An array of n monotonically increasing distance values is specified, such that distances[0] is associated with the highest level of detail and distances[n-1] is associated with the lowest level of detail. Based on the actual distance from the viewer to this DistanceLOD node, these n distance values [0, n-1] select from among n+1 levels of detail [0, n]. If d is the distance from the viewer to the LOD node, then the equation for determining which level of detail (child of the Switch node) is selected is:

0, if d <= distances[0]
i, if distances[i-1] < d <= distances[i]
n, if d > distances[n-1]

Note that both the position and the array of distances are specified in the local coordinate system of this node.

Field Summary

Fields

Modifier and Type	Field and Description
private Point3f	center
private double[]	distances
private Point3f	position
private Point3f	viewPosition

Fields inherited from class javax.media.j3d.LOD

switches, wakeupFrame

Fields inherited from class javax.media.j3d.Node

ALLOW_AUTO_COMPUTE_BOUNDS_READ, ALLOW_AUTO_COMPUTE_BOUNDS_WRITE, ALLOW_BOUNDS_READ, ALLOW_BOUNDS_WRITE, ALLOW_COLLIDABLE_READ, ALLOW_COLLIDABLE_WRITE, ALLOW_LOCAL_TO_VWORLD_READ, ALLOW_LOCALE_READ, ALLOW_PARENT_READ, ALLOW_PICKABLE_READ, ALLOW_PICKABLE_WRITE, ENABLE_COLLISION_REPORTING, ENABLE_PICK_REPORTING

Fields inherited from class javax.media.j3d.SceneGraphObject

nodeHashtable, retained

Constructor Summary

Constructors

Constructor and Description
DistanceLOD() Constructs and initializes a DistanceLOD node with default values.
DistanceLOD(float[] distances) Constructs and initializes a DistanceLOD node with the specified array of distances and a default position of (0,0,0).
DistanceLOD(float[] distances, Point3f position) Constructs and initializes a DistanceLOD node with the specified array of distances and the specified position.

Method Summary

Methods

Modifier and Type	Method and Description
Node	cloneNode(boolean forceDuplicate) Used to create a new instance of the node.
(package private) void	duplicateAttributes(Node originalNode, boolean forceDuplicate) Copies all DistanceLOD information from originalNode into the current node.
double	getDistance(int whichDistance) Returns a particular LOD cut-off distance.
void	getPosition(Point3f position) Retrieves the current position of this LOD node.
void	initialize() Initialize method that sets up initial wakeup criteria.
(package private) void	mergeTransform(TransformGroupRetained xform)
int	numDistances() Returns a count of the number of LOD distance cut-off parameters.
void	processStimulus(java.util.Enumeration criteria) Process stimulus method that computes appropriate level of detail.
void	setDistance(int whichDistance, double distance) Sets a particular LOD cut-off distance.
void	setPosition(Point3f position) Sets the position of this LOD node.

Methods inherited from class javax.media.j3d.LOD

addSwitch, getAllSwitches, getSwitch, indexOfSwitch, insertSwitch, numSwitches, removeAllSwitches, removeSwitch, removeSwitch, setSwitch, updateNodeReferences

Methods inherited from class javax.media.j3d.Behavior

createRetained, getEnable, getNumSchedulingIntervals, getSchedulingBoundingLeaf, getSchedulingBounds, getSchedulingInterval, getView, getWakeupCondition, postId, setEnable, setSchedulingBoundingLeaf, setSchedulingBounds, setSchedulingInterval, wakeupOn

Methods inherited from class javax.media.j3d.Node

checkDuplicateNode, checkForCycle, cloneTree, cloneTree, cloneTree, cloneTree, cloneTree, cloneTree, cloneTree, duplicateNode, getBounds, getBoundsAutoCompute, getCollidable, getLocale, getLocalToVworld, getLocalToVworld, getParent, getPickable, setBounds, setBoundsAutoCompute, setCollidable, setPickable

Methods inherited from class javax.media.j3d.SceneGraphObject

capabilityBitsEmpty, checkForLiveOrCompiled, clearCapability, clearCapabilityIsFrequent, clearLive, duplicateSceneGraphObject, getCapability, getCapabilityIsFrequent, getName, getNamePrefix, getNodeComponent, getUserData, isCompiled, isLive, isLiveOrCompiled, setCapability, setCapabilityIsFrequent, setCompiled, setDefaultReadCapabilities, setLive, setName, setUserData, toString

Methods inherited from class java.lang.Object

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

Field Detail

distances

private double[] distances

position

private Point3f position

center

private Point3f center

viewPosition

private Point3f viewPosition

Constructor Detail

DistanceLOD

public DistanceLOD()

Constructs and initializes a DistanceLOD node with default values. Note that the default constructor creates a DistanceLOD object with a single distance value set to 0.0 and is, therefore, not useful.

DistanceLOD

public DistanceLOD(float[] distances)

Constructs and initializes a DistanceLOD node with the specified array of distances and a default position of (0,0,0).

Parameters:

distances - an array of values representing LOD cutoff distances

DistanceLOD

public DistanceLOD(float[] distances,
           Point3f position)

Constructs and initializes a DistanceLOD node with the specified array of distances and the specified position.

Parameters:

distances - an array of values representing LOD cutoff distances

position - the position of this LOD node

Method Detail

setPosition

public void setPosition(Point3f position)

Sets the position of this LOD node. This position is specified in the local coordinates of this node, and is the position from which the distance to the viewer is computed.

Parameters:

position - the new position

getPosition

public void getPosition(Point3f position)

Retrieves the current position of this LOD node. This position is in the local coordinates of this node.

Parameters:

position - the object that will receive the current position

numDistances

public int numDistances()

Returns a count of the number of LOD distance cut-off parameters. Note that the number of levels of detail (children of the Switch node) is one greater than the number of distance values.

Returns:

a count of the LOD cut-off distances

getDistance

public double getDistance(int whichDistance)

Returns a particular LOD cut-off distance.

Parameters:

whichDistance - an index specifying which LOD distance to return

Returns:

the cut-off distance value associated with the index provided

setDistance

public void setDistance(int whichDistance,
               double distance)

Sets a particular LOD cut-off distance.

Parameters:

whichDistance - an index specifying which LOD distance to modify

distance - the cut-off distance associated with the index provided

initialize

public void initialize()

Initialize method that sets up initial wakeup criteria.

Specified by:

initialize in class Behavior

processStimulus

public void processStimulus(java.util.Enumeration criteria)

Process stimulus method that computes appropriate level of detail.

Specified by:

processStimulus in class Behavior

Parameters:

criteria - an enumeration of the criteria that caused the stimulus

cloneNode

public Node cloneNode(boolean forceDuplicate)

Used to create a new instance of the node. This routine is called by cloneTree to duplicate the current node.

Overrides:

cloneNode in class Node

Parameters:

forceDuplicate - when set to true, causes the duplicateOnCloneTree flag to be ignored. When false, the value of each node's duplicateOnCloneTree variable determines whether NodeComponent data is duplicated or copied.

See Also:

Node.cloneTree(), Node.cloneNode(boolean), Node.duplicateNode(javax.media.j3d.Node, boolean), NodeComponent.setDuplicateOnCloneTree(boolean)

duplicateAttributes

void duplicateAttributes(Node originalNode,
                       boolean forceDuplicate)

Copies all DistanceLOD information from originalNode into the current node. This method is called from the cloneNode method which is, in turn, called by the cloneTree method.

Overrides:

duplicateAttributes in class LOD

Parameters:

originalNode - the original node to duplicate.

forceDuplicate - when set to true, causes the duplicateOnCloneTree flag to be ignored. When false, the value of each node's duplicateOnCloneTree variable determines whether NodeComponent data is duplicated or copied.

Throws:

RestrictedAccessException - if this object is part of a live or compiled scenegraph.

See Also:

Node.duplicateNode(javax.media.j3d.Node, boolean), Node.cloneTree(), NodeComponent.setDuplicateOnCloneTree(boolean)

mergeTransform

void mergeTransform(TransformGroupRetained xform)