# visualaborate
_New Media & New Technology - Collaboratively_
> A project for the Media Technology MSc at Leiden University. I tried to produce art collaboratively through the phone accelerometer from participants.
Published 2011-01-17 by Patrick Heneise.
Canonical page: https://patrickheneise.com/blog/visualaborate/
visual collaboration — that was my theme for the final
‘[New Media & New Technology](http://www.nmnt.nl/)‘ course within the ‘Media
Technology’ programme.
## Final Result
With 8 participants after 5 hours exhibition time.
## Concept
I took the underlaying idea from a previous project: controlling a virtual
instance with an iOS device and be part of something big. Instead of a game I
wanted to do something more permanent and stable, so I decided to do a
visualisation. The “big picture” is a collection of peoples own preferences and
attitudes. Everybody can contribute a personal touch without artistic skills, as
the visualisation does not rely on dexterity, but pure fun and movement of the
device.
## Implementation
Instead of HTML and JavaScript I created my own iPhone App “GyroTransmitter”
which sends accelerometer- and gyroscope-data with some additional custom values
like colour and line size/number to the network as UDP broadcast.
On the other end I used Quartz Composer again, as it has very powerful
visualisation engines. However, I did not have the skills in OpenGL and OpenCL
for personalised visuals, so I had to rely on the ready-made patches from Apple.
Some things couldn’t be handled without a little bit of scripting, for example
the device queue, which holds all actual values for all devices without any
duplicates. This was rather a challenge, as it is quite confusing to work with
so many structures:
```
`function (__structure device, __structure outputQueue, __string debug) main (__structure inputStructure, __structure inputQueue) { var result = new Object(); var device = new Object(); var qObj = new Object(); var queue = new Array(); device.attributes = new Object(); if(inputStructure != undefined) { device.id = inputStructure[0]; device.attributes["ax"] = inputStructure[1]; device.attributes["ay"] = inputStructure[2]; device.attributes["az"] = inputStructure[3]; if (!_testMode) { if(inputQueue != undefined) { var found = false; for(i=0; i < inputQueue.length; i++) { qObj = inputQueue[i]; if(String(qObj["id"]) == String(device.id)) { queue[i] = device; found = true; } else { active = qObj["active"]; queue[i] = qObj; newObj = queue[i]; } } if(!found) { queue.push(device); } } } } result.device = device; result.outputQueue = queue; return result; }`
```
The base patch is pretty simple: get the values from the network, split them
into the right attributes, queue them and display them. As mentioned above,
there is some JavaScript processing required to create the queue and an iterator
to display one “_Line Family_” for each device.
## Problems with Quartz Composer
Quartz Composer can be tricky sometimes and it took me dozens of hours to debug
and get the patch running. Some information which is worth sharing about Quartz
Composer:
### No Integration or Random in Iterations
By integration I’m talking about the mathematical term. Adding values up/down,
which is a pretty simple task. However, once you’re in an iterator-patch, the
output of the Integrator-patch is always the same for all instances, so even if
one device sends to command to go down and the other one the command to go up,
they’re both doing the same. Random is also the same value for all instances, no
matter how many random generators you use. This is also valid for any kind of
trickiness you might get into your mind. I tried JavaScript, Math, Mathematical
Expression, Integrator and a complex Sample & Hold combination, nothing worked.
### No JavaScript Debugging
This is actually the worst thing in Quartz Composer: there is no debugging. If
there is a logical mistake (which is not recognised by the syntax-check), the
output of the patch is simply ‘virtual’, there is no clue on where the mistake
actually is. And as JavaScript is an untyped language, you can just write
attrbute instead of attribute and search for the error for a while.
## Conclusion
Overall I’m quite happy with the results, even if I will probably not use Quartz
Composer again and try to use the Quartz Engine with Objective-C next time. To
figure things like the iteration problem out just costs too much time and
usually works in every other language. The output of the patch and the
collaboration on a visualisation is fun, even if the network broadcasting is
still not perfect and there could be more options in the graphical device
interface instead of random values, but I wanted to avoid too much focus on the
interface, but controlling the visualisation with gyro and accelerometer data.
For future work I would display the visualisation also on the device and get rid
of interface input completely, but use simpler visualisations. These ‘_private_‘
visualisations could then be added up in a crowd-visualisation, without users
seeing the end result while they’re adding their part.
## Video
visualaborate from Patrick Heneise on Vimeo.