3D Rendering in uDig

I've started experimenting with Java3D rendering in uDig. The goal is to use Java3D as a rendering engine first for plain old 2D data, and then for real 3D data in the next step.

More details can be found in the uDig wiki.

Java3D and Eclipse

The world is not flat, and 3D maps is one of the latest hypes in navigation systems. (Is anybody using them for real, I wonder....)

So there is a need for me to deal with 3D city and terrain models in my applications, and of course the first thing you want is a 3D viewer. I started experimenting with Java3D a few months ago, and it felt such a relief compared to OpenGL programming in C. The only thing that gave me a hard time is the lack of documentation in some areas, but in the end I could answer most of my questions by studying the source code or by trial and error.

At first, I wrote a couple of stand-alone viewers with a Canvas3D embedded in an AWT Frame, but what I really need is Java3D embedded in an Eclipse view or editor.

I found a couple of postings on Java3D with SWT which sounded rather discouraging, but in the end it was rather straightforward. The java3d-eclipse project on Sourceforge gave me some useful hints, but I cannot recommend using it, since the way that it re-bundles the Java3D JARs is definitely not OSGi-compliant.

Now here is my own recipe:

• Get the sources for Java3D 1.5.2 from https://java3d.dev.java.net. There is no source package, you have to use CVS. You need three subprojects: j3d-core, j3d-core-utils and vecmath.
  
• Compile vecmath into a stand-alone OSGi bundle.
• Follow the Java3D build instructions to build j3d-core and j3d-utils in one go, including some native library compilation and Java code generation.
• j3d-core and j3d-core-utils mutually depend on each other and cannot be compiled separately, so I really don't understand why Sun created two libraries instead of one. Anyway, to be friendly to Maven and OSGi, I copied the original sources, the generated sources and the native library binaries to just one Maven project, created a POM and built my Java3D OSGi bundle using the maven-bundle-plugin.
• I did this both for Windows and Linux and managed to launch the HelloUniverse demo from Equinox.
• For cross-platform use, move the platform specific code (both the native libs and a handful of Java classes) to separate projects and build OSGi fragments for these, similar to SWT.

After these preparations, embedding a Canvas3D into an Eclipse view or editor is as easy as this:

public void createPartControl(Composite parent)
{
   awtContainer = new Composite(parent, SWT.EMBEDDED);

   Frame frame = SWT_AWT.new_Frame(awtContainer);
   frame.setLayout(new BorderLayout());

   GraphicsConfiguration config = SimpleUniverse
       .getPreferredConfiguration();

   Canvas3D canvas = new Canvas3D(config);

   createUniverse(canvas);
   frame.add(canvas, BorderLayout.CENTER);
}