How to Make a Multitouch Table - MTbiggie

The bigger brother of the MTmini, the Multitouch Biggie (MTbiggie) is a low-cost multitouch solution using:

- 2 chairs
- acrylic sheet
- paper
- projector
- mirror
- infrared camera (you can make one from a normal webcam)
- computer

Shadows on the surface are tracked and sent to multitouch applications as touch positions. This technique is known as "front diffused illumination".

While this isn't the most robust and stable multitouch solution, it is a general introduction to the technology.

For more information and software downloads see:




Video by Seth Sandler and Cyrus Ortiz-Luis
Music is "Good Day" by Triplefox

[rtwomey]

that looks great Seth. Congratulations!

[vpleric]

Great Job! Video is very easy to understand. Hope to see more in the future!

[Theoddert]

Very nice! I was wondering however what the purpose of the mirror is? Is it possible to create a similar build without it, by pointing the projector directly at the acrylic? Also, do IR cameras that emit IR light affect it in any way? Thanks :)

[hatimrachdi]

hi !! its really amazing ; but if i use a normal glass not a acrylic sheet will it work ?

[recklessness]

@jonidimo Cerupcat is using ambient, diffuse infrared light that is already there from the sun
instead of lighting the touch surface with infrared, generating points of light where your finger touches down.
The sun emits infrared light too, and the paper (or frosted glass) diffuses it.
So now, we can track for dark spots (shadows of your fingers) instead of light spots.
No infrared LED's needed. :)

[SethSandler]

@macsgotgame The infrared camera is made from a normal webcamera. You search how to make a IR webcam. The camera is placed under the table pointing up. You can see it in the video taped to the projector and pointing at the surface.

[SethSandler]

@jonidimo There aren't any because this method is using the ambient infrared light in the environment. The light and sun in the room give off enough infrared light to create shadows so that LEDs are not needed.

[Pvsmuntje]

Thank you so much! I've been waiting for this video!

[BlizzetaNet]

@cerupcat Thanks. Now I just need to order the things needed. It will take me a while to complete it because I have no money at this time, and the cost of Wood and all. When I'm done with it, I will post a response video here. You're the best man. :D

[SethSandler]

@MrDPolyak You can do single touch within applications on Windows. IT basically replaces the mouse with a touch/tap.

[mfulm]

great video guys, it workes without IR led ? and what is the paper that you have been used

[SethSandler]

@jonidimo It'll work at night if the lighting in the room contains infrared. Since the requirement is that shadows are formed, it means there must be light in the room whether through ambient light or through added infrared lights.

[madman]

this is really great, im thinking of using this idea to create an interactive tabletop for warhammer 40k. even though its been like 8 years its still a great idea :)

[SethSandler]

@macsgotgame In this example the light is coming from the environment. You need lights on around it that have IR (which most lights do). You can see the other techniques on my website or NUIGroup.

[SethSandler]

@GumDuFressen Did you add a visible light filter? You need to filter the visible light out using photo negatives or a bandpass filter.

[sirkojac]

I'm going to try this with the Eye Clops Mini projector to see if I can make a smaller setup.

[jamesdangerharvey]

I own a tattoo shop and have a huge light box with some special white laminated glass. its practically ready to go for this.

[SethSandler]

@Krisdellario It should work. As long as when you look under it you can see shadows, it'll work fine. :)

[SethSandler]

@LanteanKnight In the video, it's actually pointing at the table. However, as @recklessness1987 said, you can do either. I recommend pointing directly at the table if you're able to.

[defectoralexander]

can you browse the internet and do basically anything with that touchscreen as long as you have the projected image or does it only work with a specific program?