Virtual DJ – Documentation by Rhys Griffiths

Brief overview description

The Interactive Sound Studio project created by Serge Viranian, Rong Ma and Myself is a DJ simulation installation titled ‘Virtual DJ’. ‘Virtual DJ’ attempts to create a ‘DJ-ing’ experience for users through its ability to modify and manipulate techno music through actions such as ‘Mixing’ and ‘Scratching’.

Gloves worn by the user have various colours on the fingertips which are tracked by a webcam encased inside a three sided box with a clear Perspex top.

The data collected from the spatial movement of these colour tipped fingers is then used in the installations program, created in Max/MSP, to carry out various operations.

Here is a picture of the installation.

Design motivation

In the early stages of the course, our team initially had similar ideas to create an installation which dealt with the control of music - ‘DJ-ing’ came to mind.

In real life, DJs use their hands to control and modify music. DJ’s use their hands to manipulate vinyl records to create ‘scratching’ noises. They also press buttons and turn knobs to create various sound effects and modify the music. We figured that the hands would be the best type of controller.

Related and influential works

Whilst researching and looking for inspiration, we found numerous related compositions which utilized the Nintendo Wii’s ‘Wii remote’ - ‘Wii J DJ’, ‘Wii Conductor Hero’ and the ‘Wii Loop Machine’ to name a few.

With the success of Video Game titles such as Guitar Hero, in which users use a controller with the appearance similar to that of a real guitar, it could be assumed that users feel immersed and truly stimulated when using controllers resembling their real counterpart.

After discovering the abovementioned compositions, and with the knowledge that many of our peers would be using ‘Wii remotes’ in their projects, we decided that we would rather try to use something else as our major controller.

As we decided on the concept of ‘DJ-ing’ and because our research showed us that people liked to use a simulation of the real thing, we decided that the ‘Wii remote’ was not suitable for this purpose and that the use of spatial movements of the hand on would be better.

Technical method

The encased webcam was used to detect movement data of the coloured markers on the white gloves. Once detected, the data was used by the program created in Max/MSP.

This picture is a snapshot of the program used in the installation which was created in Max/MSP. The webcam tracks the colours on the fingertips of the gloves worn by the user and sends the data to the appropriate box - one box deals with red colours, another with blue, another with green and another with yellow.

These boxes are made up of more codes and operations. The output of these codes and operations is sent to the audio output which is in the bottom left of the picture.

This snapshot shows the process of the ‘scratching’. The data of the spatial movement of the red colours on the right hand glove is taken, and turned into an angle, as can be seen on the left hand side of the picture. This angle data then determines the playback speed of the main looping track.

This was slightly problematic because at some point the angle inverts its values making very high or low playback speeds very difficult to perform.

This snapshot is of the process of playing additional sound loops, as a result of movements of the blue, yellow and green colours on the left hand glove. If colour is detected, the trigger will change its value to true and play the sound. At the top of the picture, the sound files used in the program are being loaded.

User experience / Usability considerations

We wanted to create an experience for the user in which they felt they were being a DJ. We also wanted to create a unique and interesting interface which all sorts of people could use and appreciate.

As the installation intentionally did not have clearly outlined instructions, our goal was to create an experience where the user would be able to take the information they were receiving (the sound output) and then conclude what their movements and actions were affecting.

This worked quite well in most cases, but some users which spent little time using the installation did not completely understand what they had just experienced.

DJ’s mix and manipulate music and try to keep rhythm. Throughout the course, it became apparent that our initial proposal would be too difficult to achieve within the given time frame. We had to leave out panning, volume and tone controls and simplify the other operations.

Therefore, the main challenge and focus of the installation became trying to mix the sounds together in rhythm and for the music to continually flow – as a true DJ would attempt to do.

Resources & References

• Computer Hardware

ú Laptop

ú High quality headphones

ú Webcam

ú Computer speakers

• Computer Software

ú Max/MSP with CG Jitter Patch

ú Sound Track Pro

ú Audacity

• The Box

ú Wood: roughly 3 50cm x 30cm pieces

ú 4mm thick Perspex top

ú Portable fluorescent light

ú Semi-gloss black spray paint

ú Screws

ú Silicone glue

ú Tools and machines from University Workshop

• www.audiojungle.com
• www.freesounds.org
• www.soundsnap.com
• ‘DJ Wii J’
• ‘Wii Conductor Hero’
• ‘Wii Loop Machine’
• ‘Guitar Hero’

Conclusion

Our installation was well received at the Interactive Sound Studio Exhibition. Users commented that the installation was fun and that they had not used anything like it before. We learn valuable skills in programming, time management and presentation and also learned a lot about sound and how to use it effectively.