so after coming across the starcraft played on multitouch surface video on youtube, i was like dang, i wish i can have something like this and then i came across jeff han’s video of him doing a demo of his multitouch FTIR and i thought this was a prototype of a product coming out in the future someday like the coffee table microsoft is releasing. I then got leaded to this website and figured out this was something i can actually make that doesn’t cost crap load a money like the microsoft coffee table. So now reading a lot of the threads and such on this forum i’m actually inspired and thinking of making a multitouch myself.

So here are some starting out questions of mine:

I’m thinking of making a diffused illumination multitouch

1. What do I use as an IR emitter? IR leds? IR lamps?
2. Is an FTIR model a better choice over the diffused illumination?
3. If so, then which one’s easier to make and/or which one’s more cost efficient?
4. I keep hearing about compliant surfaces… wut exactly are they?
5. Where can I buy mylar sheets?
6. I keep hearing about people using more than one camera to detect light, should I use more than one?
7. I’m kinda confused on how everything’s arranged out…
Is it projection surface->acrylic->compliant surface? (for DI)
and for FTIR is it projection surface->compliant surface?

Thanks if you answer!

welcome to the community! i hope we’ll be seeing your progress!

i’m not really knowledgeable on diffused illumination, but i’ll answer what i can

1. not sure, both would probable work
2. depends on what you want to do, ftir works best in ‘controlled light’ conditions where DI works better in changing conditions. (controlled being where the is almost no ambient IR)
3. DI is easier i would say, you don’t need to sand/polish the acrylic or build the LED circuit. cost-wise, i don’t know
4. a compliant surface enhances the touch to an FTIR table, you get better results with brighter blobs than compared to touching the bare acrylic. not sure about DI
5. no idea
6. only if you want to, some use it to get a bigger resolution without sacrificing frames per second by ‘stitching’ the feeds together. other use it to detect fiducial markers. so that is your choice.
7. for FTIR it’s projection surface on top, then complaint surface then acrylic. DI - don’t know

hope this helps a bit

DI doesn’t use a CS.  You don’t need to worry about frustrating the light, so there’s no need to couple anything to the acrylic.

You can buy Mylar from Nevada Blue.  +1 (775) 883-6011

@donovan ..... u said DI is eaiser so i am considering DI then the next answer says FTIR so does that compliant surfaces are not a necessity for DI ??? sorry for the n00by questions but i wasnt able to find an easy how to guide

the reason i say DI is easier:
1.you dont need to build an IR LED circuit
2.you dont need a frame for the circuit around the acrylic
3.you dont need to sand the edges to get optimal amount of IR light to go into the acrylic

so it’s just far less work to do. FTIR and DI both give good results.

and with DI you can have an ‘open edge/no frame’ table like the MS surface

read the forum first, before you start asking “standard questions”

i am really sorry gravano but i have yet come across an understandable how to guide ... u see all text is very difficult to understand

i was rather referring to the opening post