Even your shampoo bottle was shaped by software that remembers why
Perfume bottles and shampoo dispensers today are shaped with methods engineers in the 1960s never imagined. Computer-aided design began as a faster drawing board and became something stranger: software that records not just a part's shape but the reasoning behind it, so changing one measurement ripples sensibly through everything linked to it.
The shift started in the mid-1960s with IBM's drafting system. Early programs mostly copied hand drafting on a screen, but soon they were producing parts lists automatically, laying out integrated circuits and checking whether components collided. Jobs that had been split between draughtsman, designer and engineer began merging into one seat, and companies could see the savings plainly.
The tools climbed a ladder of sophistication. Two-dimensional sketching let drawings be rescaled and rearranged at will, unlike ink on paper. Wireframe models extended lines into three dimensions, but every edge had to be placed by hand and the result had no mass; you could not simply drill a hole in it. So-called dumb solids behaved more like clay or wood, built by adding and cutting away cylinders, prisms and spheres.
Parametric modelling added what designers call design intent. If a hole is meant to sit at the centre of a part, you locate it from the centre, and when the part grows the hole follows. Direct modelling skips the history of how geometry was made and lets you push and pull surfaces afterwards, while freeform surfaces allow organic, body-friendly shapes. Assemblies then combine many parts into complete machines or buildings.
Design files feed straight into other work: stress simulations, instructions for computer-controlled machine tools, photorealistic renders and patent applications. Planners drop proposed buildings into photos of real streets to study blocked views and shadows. The same techniques produce film effects and jewellery. Most of the commercial market belongs to four firms, Autodesk, Dassault Systèmes, PTC and Siemens, and demand for better CAD has pushed research in computer graphics and computational geometry for decades.
Source: Computer-aided design
