Parametric Object Technology

BIM Curriculum 09

Topics

Object Technologies Techniques Solutions

Object Technologies in CAD

Non-parametric one object describes one product

Parametric one object can describe many products

Internal Objects used in the project are stored in the project file

ExternalObjects are stored in external libraries. The project file contains only

references to these elements.

Benefits of the Parametric Approach

Compact object format resulting smaller project file size

Intelligent building elements automatically following the changes of the project environment (e.g. Scale)

Design variations can be compared easily

Easy to maintain object libraries

Efficient way for manufacturers to publish their products

What is GDL?

GDL=Geometric Description Language

Parametric programming language of Archicad library parts

Made to describe 2D and 3D elements

The object’s scripts contains the 2D symbol, 3D model and text description for quantity take-offs

Highlights of GDL Parametric: one library part

can describe many objects Free: Allow users and

manufacturers to develop custom libraries

Easy to learn: Based on the BASIC programming language

Open: Objects can be imported-exported to DWG, IFC and 3DS format

Optimized for the Internet: GDL objects can be published on the Internet with free tools

What can you do with GDL?

2D symbolsMarkersZonesAnnotations

Building elementsDoors, WindowsStairs

Furniture and equipment HVAC elements

and much more..

GDL Basics: Parameters Users can define any number of custom parameters for GDL objects Different parameter types are available including length, angle and

material Users are allowed to modify the name and description of each

parameter

GDL Basics: 3D Shapes 3D shapes are described with dedicated GDL

commands in the library part’s 3D script 3D commands have parameters to change the objects

dimensions and materials

BRICK a, b, c CYLIND h, r SPHERE r

GDL Basics: Complex 3D Shapes

GDL Basics: 2D Symbols The objects 2D symbol is described with dedicated GDL

commands in the library part’s 2D script 2D commands have parameters to change the

symbol’s dimensions, shape, color, line-type and fill type

LINE2 x1, y1, x2, y2 POLY2_ n, frame_fill, x1, y1, s1, ... xn, yn, sn

GDL Basics: Transformations

2D and 3D elements are defined in their own local coordinate system

Elements can be moved by transforming (moving, scaling, rotating) the local coordinate system

ADD dx, dy, dz ROTZ beta

GDL Basics: Graphical Editing

Interactive graphical editing of length and angle type parameters

Special points (hotspots) of library parts can be adjusted in 2D and 3D views with the mouse

GDL Basics: Graphical User Interface

Scrollable Parameter List Parametric Graphical User Interface Preview Image Product Info URLs

Free GDL Tools

The following products offer the ability to use GDL objects in different environments and usage scenarios

GDL Adapter for AutoCAD GDL objects work inside AutoCAD as common AutoCAD

blocks.

GDL Explorer Utility application for viewing GDL objects and full GDL

catalogs without having to install Archicad

GDL Web Control (Plug-in) provides ways of exploring GDL objects via the internet

using popular web browsers.

GDL Publisher

authoring tool to publish GDL objects on web pages.

GDL Documentation

GDL Technical Standards

Beginner

GDL Cookbook

GDL Reference Manual

Introduction to Object making

Professional

Advanced

Sources of GDL Libraries

The Archicad Library (more then 1000 objects)

Free objects on the web

Commercial GDL sites

DXF-DWG, 3DS Libraries

Manufacturers’ sites