ImageJ ij3d package does not exist

From SnOwy - Ed's Wiki Notebook

I discovered a weird quirk for ImageJ -- ij3d-bin.jar is installed in the plugins folder of ImageJ just like it's supposed to be, along with ima3d_.jar. In this scenario, the objective is to write a plugin which imports classes from inside ij3d. ImageJ will not find the classes inside ij3d no matter what you do with the class paths etc.. The only solution is to unpack ij3d-bin.jar since it contains the source files. Move the source files into the plugins folder where the folder ij3d is an immediate child folder of plugin, then have ImageJ compile the plugin you're writing. ImageJ will then magically know to look inside the jar file -- if you look in the corresponding subdirectories rooted at ij3d, none of the .java sources are compiled -- ImageJ (or javac?) has only used these folders to learn about the expected directory structure inside ij3d-bin.jar. After this, it is safe to delete the sources rooted at ij3d. This has been tested on Mac OS X and Windows.