Parametric design

Article of 24 June 2016 

Parametric design enables organic shapes to be implemented for buildings

The Water Cube Olympic swimming pool in Beijing and the walkable roller coaster Tiger & Turtle in Duisburg clearly show that the statics and shape of buildings have left the geometric limits of straight angles and parallel walls and ceilings a long way behind. Diverse organic shapes and bizarre-looking design – fantasies in the minds of designers and architects turned reality – are possible thanks to the methods of parametric design.

With the help of CAD systems, designers and architects can create and design products and buildings in virtual space. Complex shapes and structures thus become visible in the simulation on the screen and not only in the mind of the designer. Unusual shapes are special components, however, which can hardly be produced automatically and are therefore very costly to manufacture. In order to enable a variety of design on the one hand and to produce it economically on the other, a method of design is needed that combines both these requirements.

Variable and intuitive to use

From the start of the seventies, parametric CAD systems were therefore developed for constructing machinery and vehicles – systems that can be used intuitively to a great extent. The geometry of the product model is no longer exactly saved. Its shape is stored in the computer by means of a combination of parameters and numerical variables used to specify size. A cube-shaped object, for instance, is defined by the parameters of length, width and height, a cylinder by diameter and height.

New concepts: the unique construction method opens up unlimited design options
New concepts: the unique construction method opens up unlimited design options

Future construction

The digitalisation of planning and implementation processes increases economic efficiency. Scripted geometric models are much cheaper than special components produced conventionally. The reduction of the variety of components and a simplification of the geometry and details succeeds without having to simplify the overall form. In fact, it is quite the opposite: once the models are stored in the computer, design modifications can be made directly on the screen by simply changing the numerical values or using a different combination of parameters. The same 3D software is used as for creating animations.

Digital fabrication: the software transfers the geometry of the structure directly to the tripod’s travel paths
Digital fabrication: the software transfers the geometry of the structure directly to the tripod’s travel paths

The 3D Cocooner

New methods of 3D printing are ideal as an implementation tool for parametrically designed shapes. At the Hannover Messe, Festo used the 3D Cocooner to show a prototype application for a Festo handling system, an EXPT-45 tripod. Modelled on the silkworm’s cocoon, a spinneret produces lightweight constructions freely in space made of glass-fibre bundles, covered and stabilised with UV-cured resin. The handling system, which drives the spinneret, is controlled directly from the design software. A user interface, which can be operated simply and intuitively, enables countless variations to be created from very simple basic patterns.

You can see here how the 3D Cocooner works: