E302 - INTRODUCTION TO GDL PROGRAMMING - PART II

About this course

The course "E302 – Introduction to GDL programming – Part II" continues the introduction to Archicad's GDL language with the complete development of a parametric object: a cupboard with legs, frame, shelves and three types of door. Over two practical sessions the 3D script is written directly with parameters, loops, conditionals and subroutines are incorporated, and the course finishes with the 2D representation, the grip points and the object's preview image.

Course details

This course is aimed at architects, engineers and technicians who use Archicad, who have completed Part I of the introduction to GDL and who want to create their own parametric objects. It is advisable to bear in mind the concepts covered in Part I: the GDL editor, the 2D and 3D scripts, the simple shape commands and the transformations of the coordinate origin. The first session reviews the previous exercise, creates the object with the Storage subtype, defines the general parameters (A, B, ZZYZX and frame thickness) and their ranges in the parameter script, and builds the legs and the frame with BLOCK, the ADD and DEL transformations and the FOR–NEXT loops. The second session adds the shelves with PRISM_ and a variable number of repetitions, the doors with IF–ENDIF conditionals (solid panel, bevelled with FPRISM_ and glazed with an opening), the opening angles, the simplification of the code with GOSUB–RETURN subroutines, the 2D script with POLY2_B, ARC2 and HOTSPOT2, and the preview image. The live demonstration is carried out with Archicad 27; the course explains that the working logic is the same in earlier versions, and the slides show the script as it appeared up to version 26.

Learning goals

• Structure a GDL object based on the three main dimensions (A, B, ZZYZX) and on its own parameters rather than numerical values.
• Define ranges and value lists for the parameters from the parameter script using the VALUES command.
• Build the geometry piece by piece with BLOCK and PRISM_, positioning it with the ADD, ROT and MUL transformations and returning the origin with DEL.
• Repeat elements using FOR–NEXT loops and calculate distances that respond to the parameters chosen by the user.
• Apply IF–ENDIF conditionals to offer variants of the same component, such as the different door types.
• Simplify and organise the script by means of comments, titles and GOSUB–RETURN subroutines.
• Create the 2D representation of the object with POLY2_B, LINE2, ARC2 and HOTSPOT2 grip points.
• Prepare the object for use: saving it in a linked library, hiding parameters and creating a preview image.

Curriculum