3D Technology - The third way

3D is only good for one thing, some would say - games. But all that could change in the next few years as 3D cameras and printers come onto the market at an affordable price. The 3D camera will allow you to photograph objects and recreate them in the camera itself, before transferring them to a PC. The 3D printer, meanwhile, will make it much easier for designers to create quick, cheap 3D models of the objects they are working on. Until recently there were only two ways to create 3D images - either use a 3D laser scanner to record an existing object, or use CAD or 3D rendering software to draw the object from scratch.

The impetus behind the 3D digital camera is unusual in that it comes from a software, rather than a hardware, vendor. MetaCreations - known for graphics and Web-creation software such as Painter, Poser and Ray Dream Studio - has created a hardware and software combination, the MetaFlash, that fits on to certain cameras. Minolta will be the first manufacturer to produce a 3D camera, the 3D 1500, which uses the MetaFlash and the Dimage EX as the basic unit. Minolta plans to release the camera in the autumn. The 3D 1500 has a detachable lens and so the MetaFlash hardware fits between the camera lens and the camera body, attaching at the point where the lens has been removed. The lens is then attached to the other end of the MetaFlash hardware, effectively putting it in the middle of the camera.

Working with the MetaFlash hardware, the camera does not flash once, but twice. The standard digital camera flashes to provide enough light for it to take the normal 2D image, while the MetaFlash flashes an additional series of thin lines of light. These stripes of light are then captured as a second image and the software can calculate - by looking at where the stripes are lighter or darker - whether the shape at that point is concave or convex. The second image is then superimposed over the first, and, using a technique known as structured-light-based triangulation, the software in the camera uses the information gathered from the stripes to turn the flat image into a 3D image. The geometry of this technique is, we were assured, quite easy, as the distance between the light source and the lens is constant. However, ambient light should be kept to a minimum, the object should be placed between 30cm and 1m away from the camera, and, most importantly, the object must fill the entire picture. This technology can be used not only to determine shapes, but also to pick up textures, again shown by the diffusion of the light.

This first iteration only takes images from a single view, although more than one image can be stitched together on a PC to create a complete 3D object. The next version of MetaFlash aims to eliminate this stage and to create the entire 3D object in the camera itself. Kodak plans to use this next version, which will work with a turntable. As the object is spun around on the turntable, the camera will track the surface of the object and determine how many shots it must take in order to compose a complete 3D object. The software in the camera will then stitch these views together to create an object that can be spun around horizontally.

Shots of the top and bottom of the object will, once again, have to be stitched on using a PC.

3D images captured in this way can be used for any number of purposes, although Kodak has its eyes on Internet and intranet use. For example, if you have a company that makes wedding dresses, you could put 3D images of the garments on your site, allowing retailers or customers to see how they look from all angles.

The 3D printers are a little simpler in operation. Known as concept modellers, these printers are small enough and quiet enough to sit in an office and can produce 3D models in a matter of hours. Previously, the only options available to those who needed models were either to use plastic extrusion modellers - which are only suited to certain uses - or to use stereo lithographic modellers, which are based around lasers and can only be used in a clean room, free from all dust and dirt.

Bix Computer Applications sells a concept modeller known as the ThermoJet, designed by 3D Systems. It works in very much the same way as an office inkjet works, squirting material out of a series of nozzles. However, the difference is that the image can be built up in layers to form a 3D object.

Images to be output are created in a CAD package and output to the printer as a .stl file. The printer's drivers first splice the image, cutting it into thin sections horizontally from top to bottom. Then the actual printing can begin.

The material used is a kind of wax, which is constantly heated and kept in a liquid state. The wax is then sprayed through an array of 352 jets, which move backwards and forwards across the printer. In each pass, a layer of wax 0.36mm thick is laid down. This dries very quickly and so the wax is solid before the next layer is applied.

The process is relatively quick, with the time taken dependent on how tall the model is. Bix calculates it takes around about an hour to build 1.5in of the model. So, something small like a mobile phone could be created in a couple of hours and for a cost of around £5. However, the printer does not speed up when creating smaller objects as it still takes the same amount of time for the jets to cross the printer. In fact, to increase the time-efficiency, it makes sense to print two or more models at a time - covering the 10in-square base with various models.

Once the model is complete it is still slightly warm, so Bix suggests you should leave it in the machine for half an hour or put it in the fridge to firm up.

At the moment, this kind of system is being used mostly by companies that are working on multiple iterations of the same design. So, for instance, if a client has commissioned a design for a new telephone, but wants to see four different variations on the same idea, all four can be created quickly and cheaply. Similarly, the designers can show one model to the client in the morning, get their feedback and show them a modified model in the afternoon.

In the future, it could be that every household has one of these printers in the garage and it could be put to any number of different uses. Your children, for example, could find the design for a new toy on the Internet and download it to the printer, cutting out that maddening trip to Toys 'R' Us. Or you could browse for new objects for your home and be able to print out a 3D model before you actually decided to buy them.

PCW CONTACTS

Bix Computer Applications 0115 840 4069 www.bix.co.uk

Minolta 01908 200400 www.minoltaeurope.com

Kodak 0800 281487 www.kodak.co.uk.