Using RotationInterpolator to rotate about multiple axis?

5 Message(s) by 2 Author(s) originally posted in 3d java

From: Richard

Date: Friday, November 03, 2006

Given a cube I'd like to spin

Equivalent to {buzz}.  More common among {C} and {Unix}
	programmers.

	[{Jargon File}]

it in space

<character> The space character, {ASCII} 32.

	See {octal forty}.

by rotating it about its
y-axis once every 4 seconds, about its x-axis once every 3 seconds and
about its z-axis once every 5 seconds.

Do not know how to proceed from following code

<software> Instructions for a computer in some programming
	language, often {machine language}.  The word "code" is often
	used to distinguish instructions from {data} (e.g. "The code
	is marked 'read-only'") whereas "{software}" is used in
	contrast with "{hardware}" and may consist of more than just
	code.

	(2000-04-08)

which rotates it about
y-axis

objTrans.addChild(new ColorCube(0.4));

Transform3D yAxis = new Transform3D();
Alpha yAlpha = new Alpha(-1, 4000);

RotationInterpolator yRotator =
new RotationInterpolator(yAlpha, objTrans, yAxis,
0.0f, (float) Math.PI*2.0f);

BoundingSphere bounds =
new BoundingSphere(new Point3d(0.0,0.0,0.0), 100.0);

yRotator.setSchedulingBounds(bounds);

objRoot.addChild(yRotator);

From: sanbikinoraion

Date: Saturday, November 04, 2006

I believe (and iirc there's a fuller answer earlier in this newsgroup
somewhere) that you make three transfrom3ds and use .rotX , .rotY and
.rotZ (one on each), and then do t3d1.mul(t3d2); t3d1.mul(t3d3); . So
make transform3ds for each rotational component, specifying the spin
rate, multiply them together, and then use that multiplied transform as
the transform for the rotationinterpolator.

The other option

<software> (Or "option", "flag", "switch", "option switch") An
	argument to a command that modifies its function rather than
	providing data.  Options generally start with "-" in {Unix} or
	"/" in {MS-DOS}.  This is usually followed by a single letter
	or occasionally a digit.

	Some commands require each option to be a separate argument,
	introduced by a new "-" or "/", others allow multiple option
	letters to be concatenated into a single argument with a
	single "-" or "/", e.g. "ls -al".  A few Unix commands
	(e.g. {ar}, {tar}) allow the "-" to be omitted.  Some options
	may or must be followed by a value, e.g. "cc prog.c -o prog",
	sometimes with and sometimes without an intervening space.

	{getopt} and {getopts} are commands for parsing command line
	options.  There is also a {C} library routine called getopt
	for the same purpose.

	(1996-12-11)

is to make three nested transformgroups, each one of
which is responsible for its own axis of rotation and has its own
rotationinterpolator.

Cheers,

sanbikinoraion

wrote in message:

Given a cube I'd like to spin it in space by rotating it about its
y-axis once every 4 seconds, about its x-axis once every 3 seconds and
about its z-axis once every 5 seconds.
Do not know how to proceed from following code which rotates it about
y-axis
objTrans.addChild(new ColorCube(0.4));
Transform3D yAxis = new Transform3D();
Alpha yAlpha = new Alpha(-1, 4000);
RotationInterpolator yRotator =
new RotationInterpolator(yAlpha, objTrans, yAxis,
0.0f, (float) Math.PI*2.0f);
BoundingSphere bounds =
new BoundingSphere(new Point3d(0.0,0.0,0.0), 100.0);
yRotator.setSchedulingBounds(bounds);
objRoot.addChild(yRotator);

From: Richard

Date: Saturday, November 04, 2006

wrote in message:
...

The other option is to make three nested transformgroups, each one of
which is responsible for its own axis of rotation and has its own
rotationinterpolator.

Pretty new to this TransformGroup stuff. Can you guide me to any
examples of nested transforms (especially with different rotations) ?

The idea is the same as "The Multi-Axis Spin-Test Inertia [186]
Facility (MASTIF) trainer" pictured at
http://history.nasa.gov/SP-45/ch10.htm [
http://history.nasa.gov/SP-45/p178i.jpg ]

From: Richard

Date: Saturday, November 04, 2006

wrote in message:

The other option is to make three nested transformgroups, each one of
which is responsible for its own axis of rotation and has its own
rotationinterpolator.

I persevered at bit

<unit> (b) {binary} digit.

	The unit of information; the amount of information obtained by
	asking a yes-or-no question; a computational quantity that can
	take on one of two values, such as false and true or 0 and 1;
	the smallest unit of storage - sufficient to hold one bit.

	A bit is said to be "set" if its value is true or 1, and
	"reset" or "clear" if its value is false or 0.  One speaks of
	setting and clearing bits.  To {toggle} or "invert" a bit is
	to change it, either from 0 to 1 or from 1 to 0.

	The term "bit" first appeared in print in the computer-science
	sense in 1949, and seems to have been coined by the eminent
	statistician, {John Tukey}.  Tukey records that it evolved
	over a lunch table as a handier alternative to "bigit" or
	"binit".

	See also {flag}, {trit}, {mode bit}, {byte}, {word}.

	[{Jargon File}]

	(2002-01-22)

and came up with this:

/*
* SceneGraph1.JAVA
*/

import com.sun.j3d.utils.geometry.ColorCube;
import JAVAx.media.j3d.Alpha;
import JAVAx.media.j3d.Background;
import JAVAx.media.j3d.BoundingSphere;
import JAVAx.media.j3d.BranchGroup;
import JAVAx.media.j3d.RotationInterpolator;
import JAVAx.media.j3d.Transform3D;
import JAVAx.media.j3d.TransformGroup;
import JAVAx.vecmath.Color3f;
import JAVAx.vecmath.Point3d;

public class

1. <programming> The prototype for an {object} in an
	{object-oriented language}; analogous to a {derived type} in a
	{procedural language}.  A class may also be considered to be a
	set of objects which share a common structure and behaviour.
	The structure of a class is determined by the {class
	variables} which represent the {state} of an object of that
	class and the behaviour is given by a set of {methods}
	associated with the class.

	Classes are related in a {class hierarchy}.  One class may be
	a specialisation (a "{subclass}") of another (one of its
	"{superclasses}") or it may be composed of other classes or it
	may use other classes in a {client-server} relationship.  A
	class may be an {abstract class} or a {concrete class}.

	See also {signature}.

	2. <programming> See {type class}.

	3. <networking> One of three types of {Internet addresses}
	distinguished by their most significant bits.

	3. <language> A language developed by the {Andrew Project}.
	It was one of the first attempts to add {object-oriented}
	features to {C}.

	(1995-05-01)

SceneGraph1 extends BranchGroup
{
private BoundingSphere boundingSphere;

public SceneGraph1 ()
{
super();

TransformGroup xGimbal = new TransformGroup();
TransformGroup yGimbal = new TransformGroup();
TransformGroup zGimbal = new TransformGroup();

xGimbal.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE);
yGimbal.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE);
zGimbal.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE);

addChild(xGimbal);
xGimbal.addChild(yGimbal);
yGimbal.addChild(zGimbal);

ColorCube cube = new ColorCube(0.4);

zGimbal.addChild(cube);

Transform3D xAxis = new Transform3D();
Transform3D yAxis = new Transform3D();
Transform3D zAxis = new Transform3D();

xAxis.rotX(Math.PI/2.05);
yAxis.rotY(Math.PI/1.25);
zAxis.rotZ(Math.PI/1.43);

Alpha xRotationAlpha = new Alpha(-1,
Alpha.INCREASING_ENABLE|Alpha.DECREASING_ENABLE, 0, 90,2500,200,
0,1460,200, 0);
Alpha yRotationAlpha = new Alpha(-1,
Alpha.INCREASING_ENABLE|Alpha.DECREASING_ENABLE,
0,210,2120,100,125,1425,150, 90);
Alpha zRotationAlpha = new Alpha(-1,
Alpha.INCREASING_ENABLE|Alpha.DECREASING_ENABLE,
0,320,2800,150,100,1900,640,120);

RotationInterpolator xRotator = new
RotationInterpolator(xRotationAlpha, xGimbal, xAxis, 0f, (float)
Math.PI*2.0f);
RotationInterpolator yRotator = new
RotationInterpolator(yRotationAlpha, yGimbal, yAxis, 0f, (float)
Math.PI*2.0f);
RotationInterpolator zRotator = new
RotationInterpolator(zRotationAlpha, zGimbal, zAxis, 0f, (float)
Math.PI*2.0f);

boundingSphere = new BoundingSphere(new Point3d(0.0,0.0,0.0),
100.0);

xRotator.setSchedulingBounds(boundingSphere);
yRotator.setSchedulingBounds(boundingSphere);
zRotator.setSchedulingBounds(boundingSphere);

xGimbal.addChild(xRotator);
yGimbal.addChild(yRotator);
zGimbal.addChild(zRotator);

// Set background

1. <operating system> A task running in the background (a
	background task) is detached from the terminal where it was
	started (and often running at a lower priority); opposite of
	{foreground}.  This means that the task's input and output
	must be from/to files (or other processes).

	Nowadays this term is primarily associated with {Unix}, but it
	appears to have been first used in this sense on {OS/360}.

	Compare {amp off}, {batch}, {slopsucker}.

	2. <jargon> For a human to do a task "in the background" is to
	do it whenever {foreground} matters are not claiming your
	undivided attention, and "to background" something means to
	relegate it to a lower priority.  "For now, we'll just print a
	list of nodes and links; I'm working on the graph-printing
	problem in the background."  Note that this implies ongoing
	activity but at a reduced level or in spare time, in contrast
	to mainstream "back burner" (which connotes benign neglect
	until some future resumption of activity).  Some people prefer
	to use the term for processing that they have queued up for
	their unconscious minds (often a fruitful tack to take upon
	encountering an obstacle in creative work).

	(1996-05-28)

color
Color3f bgColor = new Color3f(0.5f,0.5f,0.5f);
Background bgNode = new Background(bgColor);
bgNode.setApplicationBounds(boundingSphere);
addChild(bgNode);

// Have JAVA 3D perform optimizations on this scene graph.
compile();
}

public BoundingSphere getBoundingSphere ()
{
return boundingSphere;
}
}

From: sanbikinoraion

Date: Sunday, November 05, 2006

Have you seen this site? I found it very useful when I was starting
out:

http://www.JAVA-tips.org/other-api-tips/JAVA3d/

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Using RotationInterpolator to rotate about multiple axis?
Summary: Given a cube I would like to spin it in space by rotating it about its ... y-axis once every 4 seconds, about its x-axis once every 3 seconds and ... Transform3D yAxis = new Transform3D; ...