Multitouch surface computer full#
Multitouch surface computer software#

Acrylic can also be purchased on the web, although high shipping costs mean that it s best to try and find a local plastics dealer. We constructed our screen from a 24” X 30” X 3/8” acrylic sheet, which we bought at local plastics dealer TAP plastics. Additionally, it s lightweight, strong, and very clear (more so than glass). First, it has the right optical properties, allowing for an excellent FTIR effect. Why acrylic? Acrylic has several properties that make it a good fit for our project. The foundation of the screen is the sheet of acrylic which serves as the medium for the infrared light. maximum_pc_builds_a_multitouch_surface_computer 4/29 Each one requires a bit of work, so we ll discuss them one by one.

Multitouch surface computer software#

The webcam, which has been modified to detect only infrared light, sees this reflected light as white spots on the screen something like this:įrom that picture, software running on a nearby computer extracts a map of where fingers have been pressed on the screen, and uses that data to control multi-touch applications.Īn FTIR multi-touch table s screen is comprised of three basic components: The acrylic sheet, the LED lighting, and the projection surface. This effect, called frustrated total internal reflection is a little complicated, and involves something called an evanescent wave, but you don t really need to understand why it happens, just that it doe happen, as illustrated in this diagram: When a finger is pressed against the acrylic, it causes some of the light to be reflected down, through the acrylic and into the cabinet, where it is detected by the webcam.

Multitouch surface computer full#

The net effect of the setup described above is a sheet of acrylic full of internally reflecting infrared light.

This is a little tough to describe in words, so we ve made a simple diagram: This causes it to be wholly maintained in the acrylic. Once the IR light is inside the acrylic, it strikes the top and bottom surfaces of the acrylic at a nearparallel angle, and is subject to the effect known as total internal reflection. maximum_pc_builds_a_multitouch_surface_computer 2/29 The LEDs are arranged around the outside of the sheet of acrylic so that they shine directly into the thin side surfaces. An FTIR (short for Frustrated Total Internal Reflection) setup involves three vital components: a sheet of transparent acrylic, a chain of infrared LEDs, and a camera with an IR filter. There are several different ways to make a multi-touch surface, but we ll focus on the one that we employed: the FTIR screen. If you find the technology shown in this article interesting, you owe it to yourself to check out their forums, where you can participate in the development of multi-touch hardware and software.īefore we can get into the actual, physical construction of the table, it s important to understand just how it works. Virtually all the techniques used to create this table were discovered at the Natural User Interface Group website, which serves as a sort of repository for information in the multitouch hobbyist community. maximum_pc_builds_a_multitouch_surface_computerįirst, some acknowledgments are in order.

Check it out, and read on to find out how we did it! We re so pleased, in fact, that we put together a video showing the table in motion. Still, we re very pleased with how the table turned out. We re not going to claim to have done everything perfectly the first time, so think of this article as more of a build log than a definitive how-to. We documented the whole process, from start to finish, so that you can try building one of your own, if you re so inspired. “Future UI article be damned,” we thought, “we ve gotta build one of these for ourselves.” And so we did. The process isn t exactly simple, but the results we saw were stunning: multitouch surfaces with responsiveness rivaling Microsoft s $12,000 offering, built in a garage on a shoestring budget. There is, it turns out, a whole community of very smart folks out there on the internet perfecting the art of building DIY multi-touch surfaces. What we found that surprised us the most wasn t anything about the future of multitouch it was about something that people are doing right no.

Touch interfaces are hardly futuristic at this point, but multi-touch hardware like the Microsoft Surface or the iPhone is just starting to become a big deal, and we decided to see what big things are going on in that field. Posted at 9:00pm | by Alex Castle 193 Comments Print It all started while we were researching an article on future user interfaces. Home > Build Your Own Multitouch Surface Computerīuild Your O n Multitouch Surface Computer Build Your Own Multitouch Surface Computer