RENCI Vis Group Multi-Touch Blog

Developing multitouch hardware and applications for research and experimentation.

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RENCI Multi-Touch Table Development - Part 2

12 November, 2008 (17:00) | Multi-Touch


The touch detection for our direct illumination (DI) wall was originally based on the GC660 GigE camera from Prosilica. At VGA resolution (659 x 493), the GC660 can capture images up to 120 frames per second, but while the Duke wall used 8 of these to cover the image produced by 6 HD projectors, the table only had one camera to cover 2 HD projectors. The result was poor touch fidelity despite the high frame rate…

Prosilica GC Series camera

Prosilica GC Series camera.

We decided to upgrade to the Prosilica GE1650, which offered 1600×1200, but at only 30f fps. because of the aspect ratio of the two HD projectors combined into a single image (approx 1:1), we only capture 1200 x 1200. At 30 frames per second, the response was acceptable.

Prosilica GE1650 camera.

Prosilica GE1650 camera.

The added resolution moved us from a 1/3″ CCD (fairly standard) to a 1″ CCD, whcih limited our choices of wide-angle lenses. After some experimentation, we ended up using a Pentax 6.5mm F1.8 lens fitted with an IR filter. This was a real challenge since this lens had a fixed focus…

IR Illumination

Because of the reduced aperture and exposure setting for the camera, we used a large number of Lorex VQ-2120 Night Vision illuminators. There are a total of 14 illuminatiors in the table…

Lorex QV-2120 Night Vision Illuminator

Lorex QV-2120 Night Vision Illuminator

Early Development Table made out of scrap 80/20...

Early Development Table made out of scrap 80/20...

Early build of the Table...

Early build of the Table...

« RENCI Multi-Touch Table Development - Part 1

 RENCI Mulit-Touch Debut at SC08 »


Comment from Harry van der Veen
Time: November 28, 2008, 6:09 am

I really enjoy your blog and I like how you did the cloth around it, easy does it :) I bet it saved you a lot of time opposed to building a “hard” chassis case around it. Congrats on being at such a nice event.

Comment from admin
Time: November 28, 2008, 1:51 pm

Thanks. Actually, we did build a “hard” enclosure using plywood and laminate, but it ended up looking too much like a finished production-ready product, which wasn’t what we were looking for. Plus, it’s definitely easier accessing everything underneath using the skirt.

Thanks, again.


Comment from online games
Time: April 29, 2011, 1:24 am

Heya this is kind of of off topic but I was wondering if blogs use WYSIWYG editors or if you have to manually code with HTML. I’m starting a blog soon but have no coding expertise so I wanted to get advice from someone with experience. Any help would be greatly appreciated!

Comment from admin
Time: April 29, 2011, 9:50 am

Wordpress is WYSIWYG.

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