[ILUG] Multitouch screens and Linux

[Gerry Boland]

Hey Brian,About a year ago I experimented with Touchlib[1], involving a
frustrated-internal reflection apparatus (a sheet of glass on a windowed box
with a LCD backlight for light and a webcam in the box:) [2])

It didn't work terribly well, but that was due to my setup: fingers didn't
cause enough light to reflect to the webcam. I believe acrylic is far
superior than glass for this, but I had none to hand that wasn't horribly
scratched. My light source wasn't suitable either.

The library did succeed in making some very pretty smoke effects with the
noise however. I'm not aware of it having any tie-in with the
recent multi-pointer X, which may make it more of a toy.

I believe frustrated internal reflection is the better option simply due to
the fact that one may use a rear-projection to illuminate the screen, and
infrared light for the internal refraction, but it is much harder to set up
than the alternatives. Front & rear illumination MTs are easier to build,
but you need a IR bulb above the surface at all times, which can be blocked
out and confuse the surface quite easily.

[1] has a decent wiki on different approaches of MTs
-Gerry

[1] http://nuigroup.com/touchlib/downloads/
[2] http://www.youtube.com/watch?v=pQpr3W-YmcQ

2009/7/1 Braun Brelin <bbrelin at gmail.com>

> Thanks David.
>
> Braun
>
> On Thu, Jul 2, 2009 at 12:02 AM, David De La Harpe Golden <
> david at harpegolden.net> wrote:
>
> > Braun Brelin wrote:
> >
> >> Anyone on this list have any experience building and running multitouch
> >> screens under Linux?
> >>
> >
> > Well I don't, but this is a blog to look at:
> >
> >
> http://who-t.blogspot.com/2009/06/linux-multitouch-getting-somewhere.html
> >
> >
> >
> >
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