Open Source Interface

An Idea For A Touch Screen Conference Table

2008-07-30T15:12:45Z

Hey guys, I was thinking about the max size these touch tables could go, and was wondering if anyone had ever thought about creating an entire conference room table, or kitchen table. I drew up a quick picture in MS Paint (I don’t have anything else to draw it with here at work) and posted it below to give you an idea of what I’m talking about.

So basically it’s 4 normal sized touchtables but put together to form one. Four projectors, four webcams, one computer… which is a challenge in itself I’m sure, but that doesn’t mean I won’t give it a try. All the screens would be working together as all the projectors are connected to the same 4 DVI port graphics card and I would just have to set the screen as extended in the graphic options.

What I’m wondering is if this is the best way to go about it, or is it even possible to get touchlib and four cameras to work at the same time, and work together. If not, then could such a long table work with one webcam?

Just a thought.

Question Here

2008-08-29T10:49:57Z

what are the complications to building a full size table.. 8’ by 4.5’ for example?

Project size - What I must know

2008-08-13T09:26:58Z

Hi,

I’d like t buid or to buy a multitouch screen. The size needed for those project for tests is 80 cm x 120 cm.

What does this size mean (numbers of led needed, etc).
Where could I found the furnitures to built it.

Regards,

Bruno

Help for MT on LCD ?

2008-08-28T03:45:16Z

Hi all

It difficult to touch the acrylic and see at the computer screen, I wanna make the MT on LCD (17’’-19’’, so I can see my object and control it directly
Anybody know how to make or where can reference
Thanks.

Gerriets Optitrans, Lee 225 in a new DI setup for fiducial & multi-touch

2008-08-05T00:06:55Z

Hey everyone,

We’re constructing a new DI table and were looking into the projection surface material and IR diffusion. Currently we use frosted acrylic with some additional spray frosting layers on top, as well as another clear acrylic on top of that. Works pretty well but we are looking to make improvements this time around.

Looked into the Roscoe material but apparently you can’t track fiducials using it. BUMMER!

Does anybody know if fiducial tracking is possible using Gerriets Optitrans or the Lee 225 (I hope im not confusing the lee filter!). Do projections come out clear on these materials and does the IR diffuse nicely/evenly?

Any information you have is greatly appreciated as we are about to gather materials and build the new table shortly. Thanks a lot!

Best,

Jordan
BrickTable

Multi-touch display on top of monitor

2008-08-28T09:47:50Z

I would like to use a multi-touch screen on top of a display, not using a projector.
This means that the multi-touch screen has to be transparent and the camera can not be positioned below the screen, but at the side.

Is it possible, to use a transparent multi touch screen, without a diffuser, for multi-touch tracking?
Is it possible to use a camera from the side, not from directly below the screen?

I am looking forward to your replies!

Blob detecting without diffusor - Difficult Circumstances

2008-08-27T07:17:55Z

hallo guys,
i definitely need some help. I try to install an multitouch for an holographic screen, which is nearly just an glass pane without special optical attributes. So my problem is that i have no dispersive/diffusing element in my construction. The object i want to install the multitouch to is an glasern lectern. It has two angels so total reflection would not work with Lasers on the bottom, i think. because of the great looking glasern optic i would like to avoid any cables to be around the lectern.
I already installed a common Di setup. But i was not able to detect blobs all over the screen, only in the area I made the touchlib adjustments. A big problem is that the hole hand is in the cameras picture and i am not constantly able to select fingertips out of it.
Hopefully someone has experience with similar problems, or anyone has a good idea or tipp.
I’m thankful for ever answer!

This is how it look like:

Cheap milled steel

2008-08-26T18:38:45Z

I don’t know how many people need steel, but I was looking for stuff on ebay and came across a very nice deal on steel. I don’t know the quality or anything else concerning the steel, but I figured I would mention it if anyone had a need for it.

http://cgi.ebay.com/CNC-Laser-Cutting-Laser-Cutter-PAY-BY-THE-POUND_W0QQitemZ120296357024QQcmdZViewItem?hash=item120296357024&_trkparms=72:552|39:1|66:1|65:12|240:1318&_trksid=p3286.c0.m14

Have fun

LLP FAIL.

2008-08-25T13:31:48Z

Hello,

I’ve been trying to build an LLP LCD mt table, and so far it’s turning out to be one big fail. The LLP works, but the backlight completely washes out the camera. I’ve tried using IR blocking foil on the backlight acrylic, and I’ve also tried taking out the backlight and replacing it with TL light. Nothing works, my camera continues to get washed out. I’m starting to think it’s my camera filter (2 layers of exposed photo negative). My project is due on upcoming Wednesday and I’m slowly starting to get desparate. Does anyone have any other ideas I could try?

Also, on a sidenote; I’m using the Aixiz lasers, and I’m having some trouble focusing them. The laser itself has a black bit on the front (also used to screw the line lens on) that allows you to focus the laser beam. As far as I can tell there is no way to secure this part to keep it from unfocussing. The problem is that whenever I try to screw on the line lens, the laser gets completely out of focus, so instead of a Laser Light Plane I have more of a Laser Light Explosion which is 1) not very safe and 2) doesn’t allow me to track any decent blobs.

Please, help. :(

Having a LOT of questions about FTIR

2008-08-24T11:34:11Z

Hi,
since this is gonna be my first multi-touch table iam really worried about doing something wrong, because i also was not planning on spending thousends of Dollars
so i have some questions which i wanted to ask the comunity for helping me out.

1. What size for the acrylic plane is good?
I thought it shouldn’t be too small because iam not sure if iam gonna build a second one so if that will be the only one i should be happy with it, but also it shouldn’t be too big because of the costs. What do you think about a 100 cm x 75 cm?

2. How thick should the acrylic plane be?
I heard something between 8 to 10 mm.

3. How much power does the IR-LEDs need?
I heard in different forums it should be about 50mW/sr or greater? I was planing on setting those LEDs all around the table (4 sides) so i guess they don’t need to be too bright

4. What is better, an IR-LED with an acute shining angle or and wide?
I guess a more acute one is better because it has better internal reflection and it will get more even because i was planning on doing the leds on all four sides. Am i right?

5. What distance should i leave between each LED?
I thought at a distance of 3 cm between each LED, see Attachement

6. Do i have to put something on top of the acrylic? if Yes what?
some sort of special silicon?

7. Do i need to cover the Edges with something?
I mean when you have the acrylic in the frame (see attachments) should i maybe put some black acrylic/silicon on the edge so the IR-light is not coming out of the edges

Is a IR-Filter way better then a self-made-IR-filter?
I made one out of the black things from old picture thingies

I probably have a lot of more questions but i can’t tjhink at any more right now ... it is already quite a bit ^^
well ... i hope i get a lot of posts from helpful people =)

oh and yea i made the pictures in the attachement with SketchUp