I find that relatively often I have to check the “bible” of ArchiCad: The GDL reference guide.
In this guide in over 600 pages Graphisoft goes through the basics of how the GDL programming language works.
If you are interested in making objects for ArchiCad, this reference guide gives a detailed description of GDL, including syntax definitions, commands, variables, etc.
You can download it for yourself using this link.
Table of contents and logical flow
The reference guide starts of handling 3D objects before moving on to how to represent them in a 2D plane.
It however lacks severely in for example curtain wall and other feature objects that have become more mainstream in later versions of ArchiCad.
For those of you who have been reading this blog you’ll find that the ArchiCad curtain wall is severely under-documented in the reference guide.
Lastly before going over the various listing parameters the GDL reference guide goes through making user interfaces.
Later I’ll post some code-snippets and ideas that have helped me in the past. Making user interfaces can be tedious but with the right templates, they are a piece of cake!
GDL reference guide additions
In a later post I’ll add more information on several additions that were made to the reference guide.
For example the GDL cookbook by David A. Nicholson is a really good addition if you are tackling GDL at home.
In a very clear and straight forward fashion David demystifies several commands and codes included within GDL.
Although the cookbook was made for a very early version of ArchiCad, it is still relevant. The version in which the cookbook was written was iirc ArchiCad 8. Now we’re up to 21 already at the time of writing.
However the good thing about GDL, the GDL reference guide and the cookbook is that the language itself remains fairly static.
As a result objects written in ArchiCad version 8 will work just as fine in later versions (mind a few UI quips that I’ll go through later as well..).