IDisplay, Webcam Multitouch

[youtube http://www.youtube.com/watch?v=mlLY0zic7u0%5D

Embedded above is an interesting multitouch demo by [Lahiru]. The goal of the project was to find an easy way to retrofit current LCDs for multitouch. Instead of using infrared or capacitive recognition, it uses a standard webcam mounted overhead. To calibrate, you draw polygon around the desktop screen as the webcam sees it. The camera can identify the location of markers placed on the screen and their color. iDisplay can also recognize hands making the pinch motion and sends these as touch events via TUIO, so it works with existing touch software. It’s written in C++ using OpenCV for image processing with openFrameworks as the application framework.

[via NUI Group]

LCD Multitouch

[youtube=http://www.youtube.com/watch?v=wLztKzljMc0&feature=player_embedded]

[Jacob] wrote us to show off his latest project. He built his multitouch interface out of an LCD monitor. We’ve seen plenty of multitouch projects here, but usually they are projection style. This project uses the panel out of an LCD, with the diffusers and backlighting removed. The panel itself is fairly transparent, so a webcam with IR filter can see the light pens right through it. It does seem a bit dim in the video, we’re wondering if it is better in real life.

Phototransistor Multitouch With A Twist

multitouch

[Alex] sent us this project he’s working on where he’s building a phototransistor based multitouch input system. Though many people have built systems with phototransistors, most of them are quite large and very sensitive light and dark variances. [Alex] has done some fancy background subtraction through software. He believes his is the first to do this. As you can see in the video after the break, it seems impervious to the lamp he is moving around, and still fairly sensitive to his hand. We’re curious to see where he takes this one.

Continue reading “Phototransistor Multitouch With A Twist”

Global Hackdays: Tangible Interfaces

[vimeo=4138521]

June 6th is the date of the upcoming Global Hackday. This time, focusing on cheap tangible interfaces, mainly trackmate. They want as many people to join as possible, even if you’re not comfortable with code. We’ve covered the construction of the trackmate surface before, now build one and get in there and contribute.

Mud Tub: A Tactile Computer Interface

mud

[Tom Gerhardt] has made this very interesting mud interface for a computer.  Follow the link to see a video of it in action. It appears as though he’s using a laser grid of some kind to establish elevation. We might be way off on that though, there aren’t any details on the construction. He does mention that it is an open source hardware and software project, so maybe the details are available on request. In the video you can see it running as a projection surface where people are interacting with items directly on the mud. You can also see it being used as an external input device. People play Tetris using it in that example.

UPDATE: [Moon] reports from the ITP show that the tub has a 16×12 grid of generic pressurs sensors on the bottom. These feed into a MacBook Pro which is projecting on the surface. Despite the sparse grid, [Tom] says he gets good resolution by interpolating between sensors; it can detect a resting hand pivoting on the surface.

TouchKit Spark Released

touchkitspark

NOR_/D has just released their newest multitouch display system. The TouchKit Spark features a larger 35.4x23inch display surface than its predecessor, the Run. It uses ultrabright IR LEDs around the screen’s border for FTIR multitouch sensing. A high frame per second IR camera is included to increase tracking performance. The screen is fully assembled, but you need to provide your own projector and case. It can be built at table height or as low as 20inches. The device is designed to work with OpenFrameworks, but future software releases will have TUIO support.

Tangible, Changeable, Multitouch Controls

[youtube=http://www.youtube.com/watch?v=Smai_Z_galE]

iPhones and iPod touches have many advantages over the plain iPod. Have you ever wished you could advance tracks without looking though? That is a perfect example of where the current display/ input trends are lacking. There is no tactile feedback. [Chris Harrison], a Ph.D student at Carnegie Mellon has been working on an alternative.

His displays are rear projected and multitouch like many of the other multitouch systems we’ve seen. However, his also offer tactile feedback by changing their physical shape. Much like a vac-u-form, he is using vacuum to deform a flexible surface over different shapes. Not only are they able to do simple 2 state systems where you have smooth, then vacuumed, they can also do a third state by pressurizing the inside of the display. You can see several variations in the video.