Reasons to Construct a ReacTable

The interest started in year 2 of my course when a group in my class made a fiducial chess board. Since then I sat in on a lesson about the ReacTable and ever since I have been fascinated with the idea of fiducial tracking, which led me to discover the ReacTable.

My growing interest with this instrument gave me the initiative to find out more information, especially knowledge of how it works, with regards to the software and hardware alike.

The design of the ReacTable interests me immensely and is something very special indeed. The visual feedback makes the ReacTable look like something for a sci-fi film. It’s circular shape, the brightly coloured screen, the exciting animations and coloured transparent blocks certainly it eye candy for any observer. I assume that this very hard to accomplish, but I am keen, however, to find out more on how the ReacTable manages to put on such a light show.

As time moves on the technology will advance as will the ideas of how to use modern technology to make music. Already fiducial tracking is becoming a thing of the past, people are more interested in just finger tracking at the moment. I am keen to try to make a tangible instrument myself and join the amazing people who are responsible for creating not just fantastic musical instruments but pieces of art using their amazing intellect and creative genius.

The ReacTable: A concept

The Idea of the ReacTable was developed by four graduate students of the Spanish university of "Pompeu Fabra" in Barcelona. The young and ambitious students, Sergi Jordà, Martin Kaltenbrunner, Günter Geiger and Marcos Alonso of the music technology group, started developing this new and exciting concept in 2003.

Their aim was to make a tangible electro acoustic musical instrument, for it to be collaberative and fun to play. They say “the ReacTable started as a consept and not a technology, we first knew what we wanted to build, and then, discovered how to build it.”

In 2005 the ambitious group performed the first public ReacTable concert in the International Computer Music Conference. Since then the ReacTable has received an enormous amount of publicity and in 2006 the ReacTable got over 4,000,000 million hits on youtube and the numbers growing.

The ReacTable

The ReacTable is a new age synthesiser, the difference between the ReacTable and common synthesiser is that it works using a tangible touch screen user interface, instead of the common keyboard.

Sound is created on the ReacTable by moving pucks of different shapes and colours, known as tangiables around the translucent tabletop interface. Sound can be made and manipulated on this table by adding, removing and rotation of the tangibles and touch.

Maybe the most popular feature when referring to the ReacTable is the visual element. The tabletop is well known for its aluminous blue animated tabletop. The ReacTable’s specially designed translucent screen allows an animated projection of the musical change to show upon the glass.

This exciting instrument is fun to play and interesting to watch and holds the audience in owe and fascination over its most modern take of electronic music.

A person or group of people and create electronic musical sound collaboratively around this table and the possibilities of tweaking and adapting the musical ideas are endless.

I aim to construct my very own version of the ReacTable.

This blog will document my journey though the exciting process, with pictures, audio and video references. Please feel free to follow my adventure.

Building Blocks

Building Blocks are a common play thing for children they promote growth in intelligence and creativity.

By balancing and adding blocks of different shapes and colours the child can start to explore design and the process of creation becomes much more imaginative. Collaboratively children can play together and the process becomes even more exciting and engaging.

Now think about a table.

A table is where people gather to socialise and engage in conversation. A table is a place where great minds debate, create and write down ideas. The table is a place where artists may lay down many forms of creativity.

Children gather in school to work together around large tables. This encourages group skills such as working as part of a team, which is an important part of growing up.

The table is not just an object; it is a symbol of collaboration.

A Changing World (Musically Speaking)

The world is fast changing, a statement known to many people, especially to those who are involved within the world of technology. But what I find most fascinating is how music has changed and how it is still rapidly changing.

Music has always been reliant on technology, if man had not learned to skin an animal there would be no drums. If man had not learned to cut wood there would be no flutes. Stringed instruments are well crafted and made out of fancy material, and piano’s are highly complicated devices that are forever being modified.To call an instrument other than the human voice natural would be incorrect.

A musical instrument is anything that a person can use to make the sounds of music. Man has been developing musical instruments for thousands of years and it is possible to see continuity between the earliest instruments and the ones made today.Take the harpsichord for instance, it was made in the 14th-15th century, and is the well known ancestor of the piano. The harpsichord was very popular during the renaissance and baroque period, and most famously played by Johann Sebastian Bach.

The piano was invented and the harpsichord forgotten and since then, the idea of the keyboard has been used to evolve into instruments such as the synthesiser, which is a musical instrument that operates using electronics.

An electronic musical instrument is a musical instrument that produces sound via the use of electronics. It operates through outputting audio signal that works the speaker. In contrast with this, an electric musical instrument for example the electric guitar, uses electronics to amplify the volume of the instrument, usually this type of instrument will also have some way of manipulating pitch and note sound duration.

A musical instrument that uses electronics in this way may be inclined to include some sort of user interface to control its sound such as pitch and volume.

It is very common however for the electronic musical instrument to have a user interface completely separate, this is known as a controller and these are generally used with midi or open sound control.

Most common synthesisers are controlled though the aid of a keyboard interface similar to the one found on a piano. Even though the common synthesiser instrument looks like a piano, its function is something very special.

The ReacTable is a modern synthesiser.

With the ReacTable the user interface is something completely different, a tangible glass surface acts as the keyboard would on the common synthesiser. The ReacTable is very fascinating electronic musical instrument, with a touch screen user interface which makes it a truly remarkable electronic musical instrument

How Does the ReacTable Work?

I previously mentioned that the ReacTable makes sound when objects known as tangibles are put down on the surface of the table. Placing, moving and removing certain tangibles can determine how the music develops. Some tangibles can affect others in interesting ways; hence the name “ReacTable” and they act like the knobs on a traditional synthesiser. These tangible objects clear made out of clear plastic and have black and white pictures called fiducials inlayed within. It is these fiducials that make the tangible objects so important. These fiducials can be downloaded for free from the following website:

http://reactivision.sourceforge.net/data/fiducials.pdf

There are over 200 fiducials and each is different, they act like bar codes you see on products in a shop. But why is everyone different, why are they so important and how do they make sound? ReacTIVision
Like in a shop, when you go to a kiosk with your shopping each item's bar code is scaned so that the shop knows what you are buying and to remove it from the stock list and how much to charge for that product.

Within the ReacTable cabinet is a hidden video camera, the camera is connected to a computer which runs program called ReacTIVision.

ReacTIVision then analyses important factors about the fiducial,

1. the fiducial’s identity number,
2. if the fiducial is there
3. if the fiducial is taken away
4. where the fiducial is in regards to the centre of the table,
5. where the fiducial is in regards to other neighbouring fiducial’s
6. where the fiducial is in regards to its own axis

It is ReacTIVision's job to captures this information in a real time video stream which is why when you add, remove or rotate the fiducial something happens immediately. It is up to you, however, to program the computer to do or play something when these actions occur.
Delving a little deeper into the theory we shall learn that to ReacTIVivision is a standalone application that sends the fiducial’s information to a connection manager in order to have something we can see and hear.

Careful code must be written for the computer to understand each fiducial’s motion and give it a purpose for example:

ReacTIVision sees...

· when fiducial number one is added play sound,
· when fiducial dumber one is rotated increase pitch of sound,
· when fiducial number one is removed stop sound.

Yet none of this can be achieved if TUIO is involved.

TUIO Protocol

ReacTIVation sends the analysis of the fiducial activity to a connection manager known as TUIO protocol. TUIO's job is then to encode that information, which means that it transforms one format to another so another program can understand it, like someone translating French into English so a English man can understand.

The connection manager then pass's the translated information to a TUIO client which then in turn decodes the information. This TUIO client is available to down load in the following programming environments:

C++JavaC#
Processing
Pure Data
MaxMSP
Quartz Composer

It is the combination of TUIO trackers, protocol and client implementations that makes the ReacTable and other tangible table top musical instruments available today.
I will be programming my ReacTable using Pure Data aka PD mainly because it is free but also because my mentor knowledge in PD is advanced and he shall be helping me throughout my journey.