3D CAD technology
Developments in computer-aided design provide architects with vital tools, and could sway even the most hardened techno-sceptic, writes Felix Mara
In 1960, the critic Reyner Banham wrote: ‘The architect who proposes to run with technology knows now that he will be in fast company.’ Nowhere are his words more prophetic than in computer-aided design (CAD). Architects are now empowered by processing speeds and memory that would have been considered decadent 10 years ago. CAD’s scope and capability has put the aspirations of its developers in the grasp of its users.
A good example is building information modelling (BIM), which enables architects to create 3D models of buildings and handle construction information. This idea has been around for a long time as a feature of, for example, Graphisoft ArchiCAD and Nemetschek’s Vectorworks Architect, programs that architects have often used for 2D graphics, without harnessing their full capacity. Autodesk Inventor is now used by many practices, almost at full functionality.
Interestingly, the BIM explosion is partly driven by demand from contractors. Autodesk’s senior vice president of architecture, engineering and construction solutions, Jay Bhatt, has said this branch of the industry will have an ‘enormous influence’ on CAD’s future.
An exciting area of CAD development is solid modelling, which simulates a building’s detailed physical properties and is particularly useful to engineers and manufacturers. There are many different solid modelling packages, but here we look at Inventor and Digital Project.
How does Inventor work?
Inventor has an impressive armoury. It automatically dimensions geometry as you sketch, building a model that is parametric, i.e. retaining relationships between components, so amendments to specific areas generate automatic adjustments in the whole model, following rules that operators can manipulate. Its extensive analytical capacity includes integrated motion simulation and frame analysis and it provides interoperability between industrial designers and mechanical engineers.
Santiago Diaz, a modeller at Canadian design-and-build contractor StructureCraft, explains the use of Inventor in architect Cannon Design’s Richmond Olympic Oval for the 2010 Winter Olympics. ‘We used Inventor to make the concept model, final model, construction documents and shop drawings and to indirectly drive the automated production of roof panels by producing and sending fabrication data from the model to programmable logic controller machinery, which we had custom-designed for this project. We also used it to create material take-offs and determine information about the design, such as centre of gravity, total area of material, etc.’
Southampton drafting and modelling specialist The CAD Studio used Inventor’s ability to detect compatible elements and snap-fit them together to create a detailed inventory of the components of one of French designer Jean Prouvé’s prefabricated Maisons Tropicales, originally designed in 1951, which was assembled outside London’s Tate Modern in 2008. It’s also used by manufacturers, including KONE and Boon Edam.
Inventor, which is available in a range of suites, benefits from its integration with other Autodesk software, including AutoCAD and Revit Architecture but, according to Bhatt, despite the superficial resemblance of its interface to these packages, ‘it’s not for the faint-hearted’.
How does Digital Project work?
Digital Project (DP) was developed by architect Frank Gehry’s technology company, Gehry Technologies, using Dassault Systèmes’ CATIA as its core engine. It has up to 400 modules and a range of add-on packages, so users can tailor it to their requirements. It’s used extensively by Zaha Hadid Architects, for example on its 340,000m² Galaxy Soho mixed office and retail project in Beijing and its Seoul Dongdaemun Design Plaza project in Korea, comprising a museum, a library and educational facilities.
Associate Cristiano Ceccato says: ‘These innovative structures, and the mechanical and other services they house, are modelled in 3D using DP, which becomes a central reference point for the design and all data associated with it, an ideal repository for data from multiple sources, providing access from a single unified platform.’ He explains that it’s appropriate ‘because it operates parametrically, enabling speedy multiple iterations while automatically updating the central model geometry’. Associate Nils Fischer adds that DP
is used more for its capacity to handle large, detailed models than for its analytical functions.
Abdulmajid Karanouh, senior designer in Aedas London’s Intelligent Systems section says it used DP to model the envelope of its Abu Dhabi Investment Council project ‘because it’s the only package able to efficiently handle this amount of data […] and to construct complex dynamic components with all their parts and consider them in relation to the rest of the structure and environment’. Its kinetic solver was used to test the solar shading screen’s performance.
Solid modelling in the future
Many practices use add-on packages for modelling. Grimshaw’s London office uses MicroStation with another Bentley Systems product, Generative Components, as well as Rhino with the graphical algorithm editor Grasshopper. But Shane Burger, head of the computational design unit in Grimshaw’s New York office, which uses Revit, says it’s now experimenting with Inventor.
Many practices regard 3D CAD modelling to produce CGIs as an additional service and some are only gradually moving into 3D as a design tool. Few are ready to invest in solid modelling for analytical functions, which belong to the domains of other construction specialists. However, there is growing interest in solid modelling’s potential, indicated by the emphasis on rapid prototyping at this year’s SmartGeometry digital design conference in Barcelona in March. Perhaps detailed simulation of building materials’ components will silence criticism from techno-sceptic architects. And as more architects are making better use of software, it seems likely they will explore solid modelling in greater depth.