hello everyone!
i have been very interested in multi touch since the start of this year until recently when microsoft announce their surface computer, it made me got up and thought WOW… some of the ideas i had in my mind what a MT could have are realised by microsoft! amazing!

as i continue my research, i found gravano’s blog and have been reading his entries on building a MT. and now, i am very motivated to make one myself. hehe.
but i still have a little lack of confidence. mainly because i come from a web development background. i mainly do web designs and development. the programming i do are often just javascript, php, ajax, actionscript only. i am not an engineer and i am worry that i may have problems doing up the wiring.

apart from that, i have no knowledge on C++ either. i hope to use flash to develop MT applications but is TouchLib possible to use with actionscript since it is C++? i saw something that whitenoise had done with flash in the blog and it looks possible? i havent tried with the files whitenoise had done because i have no materials yet but i am excited to try things.

if i don’t have a projector yet, is it possible for me to try out with just a piece of glass and a web cam connected to a computer that has TouchLib installed?

hi,and welcome! yes,yes and yes.you can do everything you talked about.

1.you dont need any c++ to develop.whitenoiz added an osc app to touchlib that sends the info into an osc capable app,like flash. have a look at his flash apps on how it’s used.

2.im working on a .net multitouch framework.so if you have ever worked with c#,or visual basic,you can use that soon

3.you dont need a projector for now,you can test with a screen and cam.

sorry,last post got cut off.

4.you dont even need anything.touchlib has test input videos that you can use instead of a table.i’ve never used them,but someone on irc should be able to help you with that. its channel #ftir on irc.freenode.net

so for now you dont *really* need anything,but eventually you’ll need something.

hope that answers your questions,and gives you the confidence you need!

thanks donovan!
is the screen simply any kind of glass will work?
as for the cam, from the wiki and blog entries, i don’t quite understand by having a IR filter or something. i will have to get a web camera, and then pop off the lens and that’s it?
also, i keep hearing LEDs from the forum. what are these LEDs for since it will generate heat?

the LEDs won’t produce much heat, you have some heat coming from the resistors used to connect the LEDs and of course from the lamp of the beamer (in a complete setup). the second one will eventually disappear in the future, when LED-backlit LCD screens using overhead projector style optics for projection are available instead of beamers. this will have several advantages.

best regards

sorry but i am still not too sure why is there a need for there to have the LEDs. if a camera, a glass, and a projector are the main equipments, how would the LEDs help and what would they do by providing that little light?

the leds are put on the side of the glass to illuminate your fingers so that the cam can see your fingers.im not sure normal glass would work,but any acrylic based glass would,like plexiglass or perspex.

instead of ftir(the led way)you could use rear illumination.somewhere on the forums there is a description,as im not 100% on how that works

oh,as for the camera lens.you need to remove the infrared filter to get all the IR from the screen.

for some reason my posts get cut off today

then you need to add an IR pass filter to the camera.that only allows infrared to be captured by the cam.
you can make one by using developed photo negatives.i use that and works great

The reason infrared LEDs or any infrared light (in regard to rear illumination) are used is so the camera can distinguish between blobs from the projection, and blobs from your fingers. A normal camera will see the colors from the projection and that is not what we want. Therefore, we use the infrared light spectrum from blob/finger tracking (by shinning infrared light) and an infrared camera, so that the projection does not get in the way of finger tracking.