javax.media.j3d
Class PositionPathInterpolator

java.lang.Object
  |
  +--javax.media.j3d.SceneGraphObject
        |
        +--javax.media.j3d.Node
              |
              +--javax.media.j3d.Leaf
                    |
                    +--javax.media.j3d.Behavior
                          |
                          +--javax.media.j3d.Interpolator
                                |
                                +--javax.media.j3d.PathInterpolator
                                      |
                                      +--javax.media.j3d.PositionPathInterpolator

public class PositionPathInterpolator

extends PathInterpolator

PositionPathInterpolator behavior. This class defines a behavior that modifies the translational component of its target TransformGroup by linearly interpolating among a series of predefined knot/position pairs (using the value generated by the specified Alpha object). The interpolated position is used to generate a translation transform in the local coordiante system of this interpolator. The first knot must have a value of 0.0. The last knot must have a value of 1.0. An intermediate knot with index k must have a value strictly greater than any knot with index less than k.

Fields inherited from class javax.media.j3d.PathInterpolator

currentInterpolationValue, currentKnotIndex

Fields inherited from class javax.media.j3d.Interpolator

defaultWakeupCriterion

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_PICK, ALLOW_PICKABLE_READ, ALLOW_PICKABLE_WRITE, ENABLE_COLLISION_REPORTING, ENABLE_PICK_REPORTING

Constructor Summary

PositionPathInterpolator(Alpha alpha, TransformGroup target, Transform3D axisOfTranslation, float[] knots, Point3f[] positions)
Constructs a new PositionPathInterpolator that varies the transform of the target TransformGroup.

Method Summary

Node	cloneNode(boolean forceDuplicate) Used to create a new instance of the node.
void	duplicateNode(Node originalNode, boolean forceDuplicate) Copies all node information from originalNode into the current node.
Transform3D	getAxisOfTranslation() This method retrieves this interpolator's axis of translation.
void	getPosition(int index, Point3f position) This method retrieves the position value at the specified index.
TransformGroup	getTarget() This method retrieves this interpolator's target TransformGroup reference.
void	processStimulus(java.util.Enumeration criteria) This method is invoked by the behavior scheduler every frame.
void	setAxisOfTranslation(Transform3D axisOfTranslation) This method sets the axis of translation for the interpolator.
void	setPosition(int index, Point3f position) This method sets the position at the specified index for this interpolator.
void	setTarget(TransformGroup target) This method sets the target TransformGroup for this interpolator.
void	updateNodeReferences(NodeReferenceTable referenceTable) Callback used to allow a node to check if any scene graph objects referenced by that node have been duplicated via a call to cloneTree.

Methods inherited from class javax.media.j3d.PathInterpolator

computePathInterpolation, getArrayLengths, getKnot, setKnot

Methods inherited from class javax.media.j3d.Interpolator

getAlpha, initialize, setAlpha

Methods inherited from class javax.media.j3d.Behavior

getEnable, getSchedulingBoundingLeaf, getSchedulingBounds, getView, postId, setEnable, setSchedulingBoundingLeaf, setSchedulingBounds, wakeupOn

Methods inherited from class javax.media.j3d.Node

cloneTree, cloneTree, cloneTree, getBounds, getBoundsAutoCompute, getCollidable, getLocalToVworld, getLocalToVworld, getParent, getPickable, setBounds, setBoundsAutoCompute, setCollidable, setPickable

Methods inherited from class javax.media.j3d.SceneGraphObject

clearCapability, duplicateSceneGraphObject, getCapability, getUserData, isCompiled, isLive, setCapability, setUserData

Methods inherited from class java.lang.Object

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

Constructor Detail

PositionPathInterpolator

public PositionPathInterpolator(Alpha alpha,
                                TransformGroup target,
                                Transform3D axisOfTranslation,
                                float[] knots,
                                Point3f[] positions)

Constructs a new PositionPathInterpolator that varies the transform of the target TransformGroup.

Parameters:

alpha - the alpha object for this interpolator

target - the TransformGroup node affected by this translator

axisOfTranslation - the transform that defines the local coordinate system in which this interpolator operates

knots - an array of knot values that specifies a spline

positions - an array of position values at the knots

Method Detail

setPosition

public void setPosition(int index,
                        Point3f position)

This method sets the position at the specified index for this interpolator.

Parameters:

index - the index of the position to be changed

position - the new position at the index

getPosition

public void getPosition(int index,
                        Point3f position)

This method retrieves the position value at the specified index.

Parameters:

index - the index of the value requested

position - the variable to receive the position value at the specified index

setAxisOfTranslation

public void setAxisOfTranslation(Transform3D axisOfTranslation)

This method sets the axis of translation for the interpolator.

Parameters:

axisOfTranslation - transform that defines the local coordinate system in which this interpolator operates

getAxisOfTranslation

public Transform3D getAxisOfTranslation()

This method retrieves this interpolator's axis of translation.

Returns:

the interpolator's axis of translation

setTarget

public void setTarget(TransformGroup target)

This method sets the target TransformGroup for this interpolator.

Parameters:

target - the target TransformGroup

getTarget

public TransformGroup getTarget()

This method retrieves this interpolator's target TransformGroup reference.

Returns:

the interpolator's target TransformGroup

processStimulus

public void processStimulus(java.util.Enumeration criteria)

This method is invoked by the behavior scheduler every frame. It maps the alpha value that corresponds to the current time into a translation value, computes a transform based on this value, and updates the specified TransformGroup node with this new transform.

Overrides:

processStimulus in class Behavior

Parameters:

criteria - An enumeration of WakeupCriterion that have triggered.

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)

duplicateNode

public void duplicateNode(Node originalNode,
                          boolean forceDuplicate)

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

For any NodeComponent objects contained by the object being duplicated, each NodeComponent object's duplicateOnCloneTree value is used to determine whether the NodeComponent should be duplicated in the new node or if just a reference to the current node should be placed in the new node. This flag can be overridden by setting the forceDuplicate parameter in the cloneTree method to true.

Overrides:

duplicateNode in class PathInterpolator

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.

See Also:

Node.cloneTree(), Node.cloneNode(boolean), NodeComponent.setDuplicateOnCloneTree(boolean)

updateNodeReferences

public void updateNodeReferences(NodeReferenceTable referenceTable)

Callback used to allow a node to check if any scene graph objects referenced by that node have been duplicated via a call to cloneTree. This method is called by cloneTree after all nodes in the sub-graph have been duplicated. The cloned Leaf node's method will be called and the Leaf node can then look up any object references by using the getNewObjectReference method found in the NodeReferenceTable object. If a match is found, a reference to the corresponding object in the newly cloned sub-graph is returned. If no corresponding reference is found, either a DanglingReferenceException is thrown or a reference to the original object is returned depending on the value of the allowDanglingReferences parameter passed in the cloneTree call.

Overrides:

updateNodeReferences in class Behavior

Parameters:

referenceTable - a NodeReferenceTableObject that contains the getNewObjectReference method needed to search for new object instances.

See Also:

NodeReferenceTable, Node.cloneTree(), DanglingReferenceException