Notes on Using Java3D

To write a software project which allows 3D objects to dynamically change as the program runs, and display them in real time, there are four logical approaches you can choose from:

use openGL and C or C++ (This makes sense if you are familiar with openGL from taking a graphics course.)
use openGL and Java (There is currently no standard binding for this. GL4Java or JOGL are two popular but unsupported bindings. Sun and SGI announced over a year ago that they are working on a new official binding, but I don't know when it will be available.)
write your own 3D rendering software (Fun, but distracting from the main course material, and probably much slower.)
use Java3D and Java (Discussed here.)

The Java3D approach is the fastest to learn, I believe, so I will go over this in class. It is also worthwhile because there are other object-oriented scene graph approaches to 3D modeling that one might encounter in the future. The disadvantage of this method is that currently Sun is not doing any further development work on Java3D, so you will be learning something that is temporarily a dead language. However, it is likely that Sun will license the code to some company that will continue to maintain it (or make it open source) since there is a large base of Java3D users.

Java3D is installed in the transaction lab machines. Below is a sample torus generation and display project which you can use as a project starting point and to test if you have Java3D installed properly.

To learn about Java3D

The Java3D tutorial is here. Chapter 1 and 2 give all the information you need for basic purposes.

http://developer.java.sun.com/developer/onlineTraining/java3d/

And here are the JavaDocs:

http://java.sun.com/products/java-media/3D/forDevelopers/J3D_1_3_API/j3dapi/

To install Java3D on your own PC

If you want to set up your own environment for running and developing with Java3D, install it (the SDK openGL version) from Sun's pages:
    http://java.sun.com/products/java-media/3D/
(Currently this gives ver. 1.3.1 and since development has stopped, it may always be so...)

This puts these two dll files in the .../jre/bin/
J3D.dll
j3daudio.dll

And puts four jar files in .../jre/lib/ext/
   j3daudio.jar
   j3dcore.jar
   j3dutils.jar
   vecmath.jar

The installer seems able to find more than one version of Java to put these in (and tells you about them), but it may not find all copies of java, e.g., inside every development environment and browser. So you may also need to copy these files yourself if you have multiple Java versions.

To use the Java3D library in a project with JBuilder

To access the jar files in JBuilder, you need to create a "library", using Tools|Configure Libraries. Make a new library, name it "J3D-ext" and browse to include the four jar files. Then in any project using Java3D, include your J3D-ext library in the list of required library paths when creating the project. (Or add it afterwards with Project|ProjectProperties (Paths tab, then Required Libraries tab, and Add.)

A good test to see if JBuilder is configured and can find everything is to make a new project from existing code (File|New|ProjFromExisting) and point it to .../demo/java3D/GearTest/ or to run the following demo:

Torus Demo Program

This screen shot shows the execution of the program described in class for the rotating torus, to demonstrate how you can easily display a dynamically changing rotating 3D object. Here are the files individually:

J3Dviewer.java (main class, creates 3D viewing window)
controls.java (frame with control sliders. mostly JBdesigner output)
makeTorus.java (methods for creating torus geometry as array of triangles)
makeJ3DObj.java (creates a Java3D object from array of triangles)
xyz.java (3D vector routines, analogous to vecmath.jar but leaner)

Here is the whole JBuilder project file for you to play with, packed in a zip format:

torus.zip

And here is the compiled code packed in an executable jar file:

torus.jar

You should be able to run it from the command prompt by typing: java -jar <path>/torus.jar