com.sun.j3d.loaders.lw3d

Class LwsMotion

java.lang.Object

com.sun.j3d.loaders.lw3d.TextfileParser

com.sun.j3d.loaders.lw3d.LwsMotion

 class LwsMotion
extends TextfileParser

This class is responsible for parsing the data in a Scene file related to an object's animation and constructing the appropriate Java3D Behavior objects. For each keyframe defined for the animation in the Lightwave file, this class creates a LwsFrame object to parse that keyframe data and create the appropriate data structures. Then for each of those LwsFrame objects created, LwsMotion creates a knot value for a PathInterpolator and fills in the appropriate field. Finally, the class creates a RotPosScalePathInterpolator with all of the data from the animation. There are also some utility functions in this class for dealing with special cases of animations, such as animations that begin after the first frame of the scene and animations that define frames in a way that Java3D cannot easily interpret.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
(package private) class	LwsMotion.FrameHolder Class that associates a particular frame with its effective frame number (which accounts for animations that start after frame 1)

Field Summary

Fields

Modifier and Type	Field and Description
(package private) Behavior	behaviors
(package private) int	firstFrame
(package private) LwsFrame[]	frames
(package private) boolean	loop
(package private) java.lang.String	motionName
(package private) int	numChannels
(package private) int	numFrames
(package private) int	totalFrames
(package private) float	totalTime

Fields inherited from class com.sun.j3d.loaders.lw3d.TextfileParser

currentLevel, debugPrinter, EXCEPTION, LINE_TRACE, lineSeparatorChar, MISC, NONE, NUMBER, TIME, TRACE, VALUES, WORD

Constructor Summary

Constructors

Constructor and Description
LwsMotion(java.io.StreamTokenizer st, int frames, float time) Constructor
LwsMotion(java.io.StreamTokenizer st, int firstFrame, int frames, float time, int debugVals) Constructor: takes tokenizer, 1st frame of this animation, total number of frames, total time of animation, and the debug settings

Method Summary

Methods

Modifier and Type	Method and Description
(package private) void	createJava3dBehaviors(TransformGroup target) Create j3d behaviors for the data stored in this animation.
(package private) void	createJava3dBehaviorsForFramesSubset(TransformGroup target) Normally, we just create j3d behaviors from the frames.
(package private) void	fixFrames() The previous version of this method looked for sucessive frames with the same rotation value (mod 2PI).
(package private) Behavior	getBehaviors() Returns the Behavior object created for this animation
(package private) LwsFrame	getFirstFrame() Returns the first LwsFrame object (which contains the initial setup for a given object)
(package private) void	getMotion(java.io.StreamTokenizer st) This method parses the tokenizer and creates the data structures that hold the data from that file.
(package private) int	intMod(int divisee, int divisor) Utility for getting integer mod value
(package private) void	playWithFrameTimes(java.util.Vector framesVector) This method was added to account for animations that start after the first frame (e.g., Juggler.lws starts at frame 30).
(package private) void	printVals() Utility function for printing values

Methods inherited from class com.sun.j3d.loaders.lw3d.TextfileParser

checkString, checkType, debugOutput, debugOutputLn, getAndCheckString, getName, getNumber, getString, isCurrentToken, skip, skipUntilString

Methods inherited from class java.lang.Object

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

Field Detail

motionName

java.lang.String motionName

frames

LwsFrame[] frames

numFrames

int numFrames

numChannels

int numChannels

loop

boolean loop

totalTime

float totalTime

firstFrame

int firstFrame

totalFrames

int totalFrames

behaviors

Behavior behaviors

Constructor Detail

LwsMotion

LwsMotion(java.io.StreamTokenizer st,
         int frames,
         float time)

Constructor

LwsMotion

LwsMotion(java.io.StreamTokenizer st,
         int firstFrame,
         int frames,
         float time,
         int debugVals)
    throws ParsingErrorException,
           IncorrectFormatException

Constructor: takes tokenizer, 1st frame of this animation, total number of frames, total time of animation, and the debug settings

Throws:

ParsingErrorException

IncorrectFormatException

Method Detail

getMotion

void getMotion(java.io.StreamTokenizer st)
         throws ParsingErrorException,
                IncorrectFormatException

This method parses the tokenizer and creates the data structures that hold the data from that file. For each separate keyframe, this method calls LwsFrame to parse and interpret that data.

Throws:

ParsingErrorException

IncorrectFormatException

fixFrames

void fixFrames()

The previous version of this method looked for sucessive frames with the same rotation value (mod 2PI). If it found such frames, it would divide that interval into 4 separate frames. This fix is not sufficient for various rotation cases, though. For instance, if the rotation difference between two frames is more than 2PI, the rotation will not case a flag to be fixed and the resulting rotation will only be between the delta of the two rotations, mod 2PI. The real fix should behave as follows: - Iterate through all sucessive frames - For any two frames that have rotation components that differ by more than PI/2 (one quarter rotation - no reason for this, but let's pick a small value to give our resulting path interpolations a better chance of behaving correctly), figure out how many frames we need to create to get increments of <= PI/2 between each frame. - Create these new frames - Set the odl frames pointer to the new frames structures.

intMod

int intMod(int divisee,
         int divisor)

Utility for getting integer mod value

playWithFrameTimes

void playWithFrameTimes(java.util.Vector framesVector)

This method was added to account for animations that start after the first frame (e.g., Juggler.lws starts at frame 30). We need to alter some of the information for the frames in this "frame subset"

createJava3dBehaviorsForFramesSubset

void createJava3dBehaviorsForFramesSubset(TransformGroup target)

Normally, we just create j3d behaviors from the frames. But if the animation's first frame is after frame number one, then we have to shuffle things around to account for playing/looping on this subset of the total frames of the animation

createJava3dBehaviors

void createJava3dBehaviors(TransformGroup target)

Create j3d behaviors for the data stored in this animation. This is done by creating a RotPosScalePathInterpolator object that contains all of the position, orientation, scale data for each keyframe.

getBehaviors

Behavior getBehaviors()

Returns the Behavior object created for this animation

getFirstFrame

LwsFrame getFirstFrame()

Returns the first LwsFrame object (which contains the initial setup for a given object)

printVals

void printVals()

Utility function for printing values