Have you got the java3d jar files in your class path. Try to run the
example Java 3D progs in your demo/java3d folder. If you have recently
installed a new jdk you must reinstall java3d for that jdk as well since
java3d is installed in the extension folder of each individual runtime
You could also try to set the classpath environment variable to point to
the j3dxxx.jar and vecmath.jar files and the path to the jre/bin directory
where the jd3.dll or jd3.so is located.
Hope that does it...