Starting from version 3.4, we started developing a few GUI tools for ugp3, using the Qt Libraries. The first tool to be released is the Constraints Editor, a simple XML editor that allows users to have a preview of the individuals that could be generated using a certain constraints file.
Under Linux, if you have the Qt libraries (version 4+) correctly installed, the Constraints Editor should be compiled along the rest of ugp3 automatically. To check if everything went properly, from the directory where you installed ugp3 to, go to Frontends/thuban and look for an exectuable called ugp3-constraints-editor.
Executing the file will show you a simple GUI, with the following elements:
Clicking on Load will let you select a constraints file, while Preview will generate a random individual in the right-side window, using the constraints you are currently editing in the left-side window.
That's pretty much it! Have fun editing the XML and immediately checking the results with the Constraints Editor :-)