I have a Mac and none of the controls work in mgui. What's up?

This is a known issue with the LookAndFeel of Java's Swing library; however, the most recent releases of ModelGUI have addressed this issue by providing a Mac-specific init file called "mgui-1.0.x-alpha-mac" to avoid this issue. Ensure you have a recent version of ModelGUI installed (the fix was introduced in version 1.0.15-alpha), and that you are using the correct execution file.

There is a second issue with Java3D, such that the older version of Java3D installed on Mac OS X overrides the version included with the mgui library. This causes functions such as picking to fail. The workaround for this is outlined here: http://www.openifctools.org/Open_IFC_Tools/mac_java3d.html