"Endlighten Acrylic costs slightly more than regular acrylic “
slighlty?????  Transparent costs - 26,95 EUR, Endlighten - 78,95 EUR (1000mm x 500mm).

Ok i’ll fix that.

Remember though, that the cost put into IR Illuminators could be put into the cost of the endlighten and therefore the cost of DSI vs. DI/FTIR isn’t really that BIG of a difference.

This is a great post for newbies like me!!!

Thank you cerupcat.

Someone told me there were other techniques based on a pure optical solution:

http://digitable.imag.fr/
http://iihm.imag.fr/demos/presse/07_TeleGrenoble_Julien.mp4

Are this kind of techniques considered by NUI Grup community?

Thanks for the kind words MONO.

The digital table is actually using two techniques. It combines a non-optical product the “diamond touch” with a second optical tracking technique. So that isn’t a purely optical approach because they’re using the diamond touch for most of the sensing.

The second link, im not 100% what they’re doing. It looks like they’re just using image processing techniques with a single camera above the surface. This generally takes more computing power since you have to do a lot more filtering and image processing to figure out where a finger really is. Also, the room for error is larger since you don’t know when the finger is really touching the surface in this case.

These techniques haven’t really been explored by NUIGroup, but all techniques are considered. In my opinion, there’s no real benefit to a purely optical technique (although, the techniques we’re using are optical sensing techniques just not like the ones you posted).

They still can see when the finger touches the surface because they are using the lasers, remember. I wanted to try something like this over the summer but never got around to it. This would let us use any screen we wanted without having to take out the back light and disassemble the whole thing and risk killing the screen.

100 POSTS!!!

haha

cerupcat - 22 May 2008 10:49 PM

o EndLighten Acrylic
o LEDs
o Projection Surface (tracing paper, lee filter, geriets optitrans , etc);
o Infrared Camera/Modified Webcam

Hey, Cerupcat.
As I still learning things I am looking for suppliers in my country, that is an important point (Not all the materials are available here in Colombia) so depending on availability of the components (among other things like cost, time to develop, etc) I’ll choose the technique for my MT device.

In your post for DSI Parts List you said that “geriets optitrans” is a usable projection surface. I googled it but it didn’t find anything. English is not my native language so I don’t know what is that material. Would be great if you could tell me which is your supplier for geriets optitrans!!!

Other thing, It isn’t clear for me why a Rear DI Setup need to be Enclosed?

I think that would be useful to add First Surface Mirrors to the Parts List, because I think that there are very few devices that may use the space they want, space is always a constraint for many applications.

I don’t know if the four techniques require a hot mirror for the projector, If so, would be useful to add it too.

Thanks in advance

Andres Caro

maybe you could add the touchless wall...

Hi! Is FTIR better than DI? thanks.

Hi everyone, I have a doubt in the LCD FTIR method that is probably stupid, but I’m just starting my project using LCD, so here I go!
How can the images appear in the surfcase if this one is not transparent?!

Thank you!

Maruggi

Nubii,
No one method is better than another. Its really personal preference. Check out the pros/cons section to decide for yourself - FTIR requires a few more items...compliant surface, IR LEDs...LLP is easy to get set up but dangerous...DI is harder to get even illumination...its all a matter of what you’re looking for.
good luck
rbedi100

Rafael,
you have to take apart the LCD and remove the plastic casing and other opaque stuff behind the actual screen. The actual LCD matrix IS transparent. If you decide to use a compliant surface (some people say you don’t need one for LCD FTIR...), it also needs to be transparent.
rbedi100

Thank you very much for your answer rbedi.
The LCD matrix it’s ok! My doubt was in case of using a compliant surface above the LCD, and you helped me a lot!! 
Do you know what kind of compliant surface can I use in this case? I’ve read Mylar is transparent, is that true?! There is another compliant surface that I can apply in this case?!

Thanks again!
Rafael

Rafael,
I am building a LCD FTIR myself, and I was having similar questions. A couple people told me that you don’t need a compliant surface for LCD FTIR (Geoman, bridgeyman, and nima have all done LCD FTIR w/o compliant surfaces), and johannes.schoening told me that too. So, I’m going to build my table w/o a compliant surface, and if I find I need one, I’ll go from there.

Here’s the thread in which johannes gives me some links about not needing a compliant surface: http://nuigroup.com/forums/viewthread/3161/ .

About Mylar, I believe it is transparent...here’s a link to a post with a chart that is looking into the qualities of transparent plastics (acetate, mylar, lexan polycarbonate...): http://nuigroup.com/forums/viewthread/2892/ (scroll all the way down). I have a piece of Lexan that I’m going to try out this weekend but home depot didnt have any Mylar…

well...hope this helps
rbedi100