Object Making with ArchiCAD GDL for Beginners by David Nicholson-Cole BUDAPEST • MUNICH • SAN FRANCISCO • TOKYO • LONDON • MADRID • SAO PAULO • SANTIAGO DE CHILE i Object Making with ArchiCAD: GDL for Beginners © 2000. Written by David Nicholson-Cole. All rights reserved. Reproduction, paraphrasing or translation without express prior written permission of Graphisoft is strictly prohibited. Back cover credits: Marks Barfield Architects, creators of the British Airways London Eye, http://www.marksbarfield.com. GDL model by David Nicholson-Cole. Published by GRAPHISOFT R&D Rt., http://www.graphisoft.com First printing. Printed in Hungary. The version of GDL described in this manual is compatible with ArchiCAD 6.5 and ArchiFM 2000. ArchiCAD and ArchiFM are registered trademarks and StairMaker and GDL are trademarks of Graphisoft. All other trademarks are the property of their respective holders. ISBN 963 00 3726 2 ii About this Book Object Making with ArchiCAD is designed to help you get more enjoyment and productivity from ArchiCAD by taking you beyond the confines of the Toolbox (the tools palette) into the realm of object making with GDL (Geometric Description Language). Objects – such as furniture, doors and windows, lamps, building components – can be made using the existing tools – wall, roof, floor, mesh, etc. They can be made with native GDL, scripted from start to end; or they can be made with a combination of the ArchiCAD tools and scripting. ArchiCAD users have long asked for a book that will lead users from tool using to object making, and we hope that this little primer will open up new worlds for each user. The book is not just about GDL; it starts with object making using the existing tools, and by progressive stages, leads you into GDL, but we hope you will find the transition enjoyable. Some of the examples used in the book will be available from the support website. About the Author David Nicholson-Cole is an architect and teaches at Nottingham University in the UK. He has been an enthusiastic evangelist for GDL and a prodigious producer of GDL objects since discovering the power (and the pleasure) of GDL. He made his mark in the GDL world as the author of the GDL Cookbook, is a director of The-Object-Factory.com, and a founder member of the GDL Alliance. The GDL Cookbook logically follows after the book you are now reading. It is an A-Z of GDL technique, and is usable in its own right as a GDL manual. David has also travelled around the Globe at the invitation of ArchiCAD dealers and their customers, teaching GDL. Acknowledgements Object Making with ArchiCAD: GDL for Beginners was developed in concept by Graphisoft as a means of filling the gap between the GDL Cookbook and the existing reference manuals. It contains easy to follow exercises in object making, and pulls together wisdom about object making from other sources, including the reference manuals, for which all the authoring team should be thanked. iii iv Chapter 1: Introduction to Object Making Chapter 1 Introduction to Object Making An introduction to the possibilities of object making in ArchiCAD, with or without GDL. Object Making with ArchiCAD 1 Chapter 1: Introduction to Object Making 1.1 About Object Making The real 3D world can be thought of as a vast assembly of objects. ArchiCAD’s 3D environment can be thought of as a large theatrical stage where you assemble the cast (the objects), the set (the drawing) and the script (the design idea). You bring the objects together, organize them, and then – let the play begin! Most of the objects in the ArchiCAD assembly area are building elements – walls, columns, floors, roofs, meshes, etc., brought together to form buildings. These objects are easily made with the tools given to you in ArchiCAD. Whenever you need go beyond walls and floors, etc., you can use special objects such as furniture, windows and doors, lamps and components. In ArchiCAD manuals, these are also referred to extensively as Library Parts. These can be found in your library or made specially. So, why should we bother to make objects? Well, we can make: – Structural elements that are right for their purpose – Details of building construction that look authentic – Furniture that is smart and elegant – Components that conform to catalog numbers and manufacturers’ specifications – Lights that can transform the environment of a model – Windows that open and swivel, and offer a choice of styles – Doors that offer choices of ironwork and glazing styles – Stairs that enable you to vary landings, risers and handrails – Picture objects that can be placed in a model to look like people, trees, or even whole buildings – 2D drawing objects and tools that can enhance your productivity and drawing accuracy. In short, the pleasure and productivity of the ArchiCAD user can be greatly enhanced with objects. This book is intended to ease the ArchiCAD user safely into making objects. It is not entirely self contained; it needs to be read with the GDL Reference Manual and the main ArchiCAD Reference Guide. Dip into these when you need to. If you wish to take object making further, your next stage after this primer is to work with the GDL Cookbook, which takes you progressively into more advanced GDL. 2 Object Making with ArchiCAD Chapter 1: Introduction to Object Making Library Parts in ArchiCAD When you build an ArchiCAD project, you can use the primary modeling tools – walls, floorslabs, columns, roofs, etc. The Toolbox also offers access library parts: furniture objects, lamps, windows, doors. In the Toolbox or the Tools menu, you may also find add-ons such as ArchiSITE, StairMaker, Profiler and RoofMaker. To place an object in the project you can use different actions, such as click and stretch, click and click again to indicate direction, or you may encounter an entire dialog box containing instructions and many fields in which to enter information. In your use of ArchiCAD, you will have noticed that most library parts offer many chances for variation (called parameters) such as the number of mullions in a window or glazing styles in a door. They may also offer different ways (in materials, pens and fills) of representing themselves in the 3D view and in 2D. This introduction to object making will make it possible to build objects yourself; it will introduce techniques for making more than just 3D or 2D shaped objects – you can try to make them capable of offering variations – thus they can be parametric. Libraries must be loaded Whatever you make, however you make it, ArchiCAD must be able to find the object. Every time you open ArchiCAD, it reads through the library directories (folders) and makes an index of what it finds. The existing ArchiCAD Library is a folder in your installed ArchiCAD directory. ArchiCAD’s own library will be loaded (by default) but when you are running a project, or experimenting with GDL, you should make additional folders of your objects. Make sure you do not make objects or folders with the same names as ones that already exist in the libraries. When you are working with ArchiCAD, make sure that the folder you are saving your objects to is one of your loaded libraries. You can either make a new library folder that relates to current projects, or your objects can be stored in a personal library in the ArchiCAD folder. The main point is that you know where they are, and you have loaded them. Subfolders to keep furniture objects, building components, window objects, textures, etc., should be logically organized. Object Making with ArchiCAD 3 Chapter 1: Introduction to Object Making Sources of Library Parts The ArchiCAD Library It is worth going through the ArchiCAD Library included with your package before you start creating library parts on your own. Investigate what already exists. This will give you an idea of what you can use and do not need to make; and the example in there will give you ideas of what is possible. You will be able to see how parameters change and this will make you think about what qualities you might like to include in objects that you make – such as user friendliness, clear organization and description of parameters, stretchiness, 3D authenticity and intelligible 2D symbols. Complementary Libraries Several specialist libraries are available on CD from Graphisoft or their partners (e.g., People and More, MasterLibrary, etc.). If you explore the Internet, you will find an increasing number of websites devoted to ArchiCAD objects including The Object Factory (www.the-object-factory.com) or Objects On Line (www.objectsonline.com). The Graphisoft website gives you an up to date list of addresses of such sites. You will find that, with the free GDL Object Web Plug-in, ArchiCAD objects can be viewed in a browser, changed parametrically, and rendered, almost as if you were examining them from within ArchiCAD. DXF and DWG Libraries Most building component manufacturers offer disks of DXF files although most of these are 2D only. It is always worth getting these, as DXF files can be used in ArchiCAD, and you will be able to make use of them. 2D DXF and DWG can be brought straight into the Project plan. Where you see the opportunity to make library parts out of DXF or DWG originals, you may be able to take advantage of the parametric power available to you in GDL. For 3D, you can also make objects with other applications from 3rd parties – Zoom, Alias Wavefront, Design Workshop, AutoCAD – save them as a DXF, then bring them into ArchiCAD as a library part. The DXF/DWG Conversion Guide included in your ArchiCAD package explains this procedure in more detail. 4 Object Making with ArchiCAD Chapter 1: Introduction to Object Making When you bring the 3D DXF into ArchiCAD as a library part, you can opt for: – Don’t Process: The object does not get converted to 3D. Only the 2D parts will get imported. This is the default setting. – Binary 3D: The object comes in as 3D, but it is encapsulated into an uneditable block of machine code that is neat, tidy and stretchy (and more reliable when rendering), but leaves you no opportunity for further editing or parametric modifications. – GDL Script: With this option, all the 2D and 3D data will be imported, but you will be faced with a colossal quantity of script. Nothing brought in from DXF is solid; it is a vast mass of polygons and lines, and in no particular order. If you attempt to edit these you will need a lot of luck and guesswork. The most you can be sure of editing successfully are Material names, and a simplified 2D symbol. You may be disappointed with the result. You will have to spend a lot of time learning the new applications. 3D objects made in other applications will leave you with little or no control over the materials and parametric properties. In particular, you may find that the lack of control over the number of polygons leaves you with a model that has so many polygons that your rendering times become unacceptable. With such an excess of polygons, you may find it difficult to export your ArchiCAD model to a 3rd party renderer such as Art•lantis Render. If you take the time to learn GDL, you have the advantage over other CAD users, in that you can make a 2D or 3D library part in GDL that is parametrically variable, and save the resulting varied forms as separate DXFs. Add-ons that make Objects There are a number of third party programs that can create or edit ArchiCAD library parts, for example, StairMaker and ArchiSite. You will also find a growing number of object-making Add-ons provided by Graphisoft such as RoofMaker and Profiler. Objects created by these Add-ons contain GDL scripts as well as other, application-dependent data. Object Making with ArchiCAD 5 Chapter 1: Introduction to Object Making 1.2 Making your own Library Parts Without GDL – using ArchiCAD’s Tools Walls, Floorslabs, Roofs and other ArchiCAD 3D tools are available in the Toolbox as custom building blocks, regardless of their originally intended purpose. You could, for example, model a dining table easily by using walls and slabs. The legs could be tall, small slabs, or short walls. The tabletop would be a slab. If the legs were splayed as in a trestle table, you could use the Roof tool. The resulting structure can be saved as a library part, thereby making it available for repeated use in other projects as well. Library parts originating from the floor plan can be saved either as GDL scripts or in binary format. GDL scripts are editable, so you can enhance the library part’s 3D appearance by modifying its script. You can do useful work on a GDL script, mainly in editing materials and pen values. Binary library parts offer lightning fast imaging speeds, but do not allow editing, and have no parameters other than ones enabling stretchiness – width, depth and height. If you want to perform other modifications, you must return to the original floor plan document, modify the model, and save it again as the same or as another binary library part. If you save floor plan elements as a GDL script, the complexity of the resulting script will depend on the element types you have used. The Slab tool will produce a mass of CPRISMs, which are relatively easy to modify. The Wall tool will create XWALLs which are harder but not impossible to modify, but are easier to build with in the first place. The Roof tool creates CSLABs which are manageable. Some of the most interesting possibilities are with the Mesh tool, which makes commands called MASS, allowing one to create rounded surfaces. Sometimes the objects you make by assembling pieces of floor slab, wall and roof are more easily built on their side, rather than upright. Windows and doors can be built flat on the floor and ArchiCAD will convert them to be upright. Sometimes you will not be able to make an object all at once. You may have to make the legs first and save those, then make the superstructure, save that, then make additional parts, and save them. There are primitives such as cylinders, cones and domes in the ArchiCAD Library that you might also use as part of your object. You can then bring all those subsidiary parts together in the 6 Object Making with ArchiCAD