p.s. Sorry for the ending it wasn’t me!

A few weeks ago I made some adjustments to make it compatible with the latest touchlib and this is the result:

tDesk v2 allows the user to move and resize multiple windows at the same time by using multi-touch gestures. Because Windows XP/Vista was not designed for multi-touch there are some issues with this type of input. In multi-touch mode it is not possible to do a mouse click, therefor I added an option to switch between multi-touch and mouse simulation mode.

Please keep in mind that when the mouse simulation mode is activated only single touch input is allowed. Do not use this software on unstable multi-touch systems.

Finally, use this software at own risk .

Install instructions are in: readme.txt !

Downloads:
tdesk v2
Touchlib compiled libraries, revision 393 speedfix

Any tips or problems can be posted in the comment section.

* update *
In some cases tDesk does not seem to work properly with touchlib. Try downloading rev393 and overwrite your current touchlib dll files.

A few weeks ago I was busy tweaking the Touchlib sourcecode and noticed a bug/feature in the code which caused the image processing pipeline to stall for 32 milliseconds. This might not sound like a big issue however on our system it caused the system to be less responsive.

I have compiled a version without this ’sleep’ function. This version might not be safe for single core cpu’s (I could not test it out myself, hopefully someone could check it out). Because the sleep function is removed, the videoplayback (using cvcapture + *.avi)  is not working properly.

Check out this version of touchlib and report any problems in the comment section !

Download:
Touchlib (speedfix) compiled libraries, revision 393 speedfix (21 apr 2008)

MMA Pro v2d

Changelist:
- Added smoothing, scaled images should look a lot better
- Added an View Reset and Exit button
- Increased the size of the canvas
- Compatible with Adobe Air v1.0

Install instructions are in: readme_pro.txt !

Download:
Multitouch Media Application Pro v2d
Adobe AIR - required

Example video showing how to load photos dynamicly into MMA Pro

Wong!

Wong is a game based on pong which uses the multitouch input to create dynamicly sized paddles.

A game of Wong on our multitouch table:

The game is made by Seth Sandler and is part of the audiotouch application suite: http://code.google.com/p/audiotouch/

One of the demo applications which comes with Touchlib is Smoke. The technique which is used to create ’smoke’ is based on the algorithm presented by Jos Stam in his paper Real-Time Fluid Dynamics for Games.

Often multi-touch enthusiast use this application to demonstrate their multi-touch displays.

Some time ago I modified the Smoke application which allows users to draw objects into the scene. The application is extended to have a new drawing mode which is allow (multiple) users to draw objects/boundaries into the scene. This can be done while the simulation is running. If sources are placed in the scene this means you can view in real-time how flow will behave on a particular shaped object.

In the demonstration video I have added 3 different coloured sources and the logo of my university is used as an object to perform the simulation on.

A higher quality wmv can be downloaded here:
RTFD.wmv

Multi-touch video puzzle game

I had this idea for a while and even the basic puzzle game framework (using photo’s) was already finished. After messing around with FFmpeg I managed to export the video frames from an mpeg2 (.vob) file and convert them to an OpenGL texture. The only problems left were the synchronization and the audio stream. Because FFmpeg is really horrible coded (you need special hacks to get it even to compile under windows), I never managed to get those working. For those who are interested, this site: dranger.com has helped me a lot.

After searching around for an alternative I decided to drop the cross platform support for this application and use MS DirectShow. Usually I do not like the DirectX due its ‘clean’ coding style. But after giving DirectShow a try I was surprised how easy it was to get a basic demo working which played a mpeg2 file without any problems. The audio and video streams where synchronized automatically.
With some help of a friend I merged the video player code into the puzzle application.

This is the result (recorded with Fraps):

In the video I used the mouse as input device, but the application works with the multi-touch table as well.

And as usual: Don’t forget to read the readme_pro.txt !

Download:
Multitouch Media Application Pro v2c
Adobe AIR - required

Last saturday MMA Pro was presented on national television (NED3, VPRO) in the show called “In de ban van ‘t ding”. The documentary created by Dahl TV and Bright Magazine is about the (new) technologies which have an impact on our daily lives.

In this weeks episode Erwin visits SOCO Amsterdam. SOCO (Social Contemporary Center for the Arts) is a new exhibition/project space in Amsterdam. Peter Distol and Ralph Das are giving a demonstration of the table we have build together at the SOCO. The table uses front illumination and touchlib for touch detection and processing.

A part of the episode can be viewed here (it is in Dutch):

The whole episode can be viewed here:
Uitzending gemist

The applications which have been demonstrated:
- Smoke (basic demo from touchlib)
- Newswell (Ralph Das)
- Multitouch Media Application (showing Jimi Hendrix!) (Laurence Muller)

Currently there are two multi-touch tables available to the general public.

Multitouch Media Application Pro Update

The previous release of MMA Pro only worked with Adobe AIR beta1. A few users have contacted me about the troubles when installing MMA Pro v2a with Adobe AIR beta3 installed.

I have updated the application to make it compatible with Adobe AIR beta3 (Thank You Adobe! for renaming zillion functions).

The application requires Adobe AIR beta3 runtimes, so do not forget to install them first. Besides the fixes, there is nothing new.
Ofcourse this version also supports adding images on-fly. Just connect your digital camera (or memorycard) and all your images will be downloaded to the desktop. Your camera should be using the DCIM standard).

Don’t forget to read the readme_pro.txt !

Download:
Multitouch Media Application Pro v2b
Adobe AIR - required

This is the result

* update: 23 november 2007 *
Using the plugin on my multitouch table (diffused illumination) at the University.

At the beginning of september I got hold of a short-throwing-distance beamer (digital projector) of 3M (type 3M DMS 700). The specifications looked pretty impressive, and we could finally get rid of the mirror… However during testing the hardware with our new firewire camera (less latency than the Philips spc900nc) we noticed that there was a (noticable) delay between touch and display on the table surface.
Comparing the input of the firewire camera on our CRT showed barely any latency, so perhaps the issue was on the beamer…
We decided to create a latency measurement tool based on this paper. The application moves a bar at a fixed speed along 60 positions in the screen. The screen refreshes 60 times per second (the beamer runs at 60Hz max). To measure the difference it is required to take a photo of the CRT display and the result of the beamer in one shot. The difference in position (of the bar) can be used to calculate the latency.

Our test results:
3M DMS 700 (1024 x 768) - about 100ms
Canon LV-S1E (800 x 600) - less than 16.67ms

So it seems like our simple Canon office beamer has barely any latency compared to our 3M short throw beamer. If this is an issue depends on the purpose of your multitouch table. If you are planning to use it on non time related task such as a simple photo application or the puzzle application the 3M latency might not be a problem at all. If you are planning to measure the performance of multi-touch table devices this might be something to think about.

Because I could not find much information about latency of beamers in general (as far as I know, no manufacturer specifies this in the manual) I would like to ask if multi-touch enthausiasts could measure there own beamers. Below at the download section I have included the measurement tool.
All you will need is a camera which is capable of setting the shutterspeed manual (it needs to be 1/60 sec). Please post your results in the comments sections. Don’t forget to include a nice photo and some details about the used beamer (brand, type, native resolution, throwingdistance, etc…).
Note: you will need to turn on vsync in your display controlpanel.

Hopefully we will be able to make a list of recommended beamers here .

*update today@23:40*
My multi-touch developer friend Pawel ’solydzajs’ Solyga just submitted an update to the BMLT application.
New version (v0.2) with additional features:
- command-line parameters instead of static values in main.cpp (which
requires recompiling)
- print usage when wrong number of command-line parameters
- makefile for Mac OS X (tested, works nice)

Downloads:
Multitouch Puzzle Game

Beamer Latency Measurement Tool v0.2 - windows binaries
Beamer Latency Measurement Tool v0.2 Sourcecode - linux/mac os X users should build the tool manual, Makefiles are included

Discussion at nuigroup forums [link]

Howto: Compile Touchlib in Windows
Howto: Compile Touchlib in Linux

Both compile instructions apply to subversion rev.73 of touchlib. If you followed the Howto’s and still have some trouble please post the problem in the comment section.