Although I am a long time ARCHICAD user, I have seldom explored much object development beyond simply saving elements as GDL objects. There are many great resources out there for learning GDL, but I have found most of them to be overwhelmingly complicated and poor at explaining what the commands they describe really do and how to use them. Most are not beginners guides to GDL. There are great ways to make custom objects much more usable and versatile with only a handful of commands.

This guide starts at the very beginning; saving a collection of elements to GDL. It then explores manipulating the automatically generated scripts and parameter lists to make the object more versatile.

There is very little real “script writing” involved in any part of this guide, and most of the script required can be copied and pasted, then modified. Almost all objects I make are modeled, then saved to GDL and modified, so there is very little scripting necessary.

The only skill set you need before you start learning GDL is the ability to model a desired geometry, symbol, shape or object in native ARCHICAD. From here, saving to GDL is a simple process. Once you become comfortable with these steps to create quality objects and libraries, it is easy to start adjusting and manipulating these automatically created scripts to do much more than their original parts could do.