When in Dome is a geodesic dome filled with lights that responds to the movement of people inside, providing a space for shared interaction.
This was largely a solo project, which I designed and built from start to finish and then took to several festivals and exhibitions.
Anyone inside the dome can turn a wave of the arm, tilt of the head or twirl of their whole body into a performance for others to watch.
Movement is tracked by a Kinect camera sensor and the lights respond to movement in real time, using my own custom built software, written in Processing and the LEDs are driven using Fadecandy.
Building the dome
I built the dome using injection moulded hubs made by BuildWithHubs, and sawn timber struts which I cut to size and painted black.
I added vertical legs to raise the dome off the ground for better visibility of the lights, and added aluminium flat bar cross brackets between each leg for stability.
Planning the lights
Using a 3D model in SketchUp, I experimented with options for the layout of the LED strip. The layout had to take into account aesthetics and also distribution of power and data.
The geodesic dome is a 2V style, meaning it has two types of triangles. I used a design of concentric triangles on the equilaterals and parallel lines on the isosceles.
Data and power
I used 11 Fadecandy chips to drive data. Each one can control up to 8 strips of 64 pixels, so the lines on the panels were divided over these strips. I also used 11 power supplies.
To organise distributing power across the dome and to hold the Fadecandys, I made 11 small control panel units. Each one runs 3 triangle panels.
Soldering the LEDs
Each piece of LED strip needed lengths of cable to connect power, ground and data from the supplies and on to the next strips. These lengths varied depending on the position of the strip so I made a spreadsheet to quickly reference what length of cable was needed, and to track my progress through soldering them.
Altogether I logged around 23 hours of soldering.
Creating the panels
The panels were cut out of thin plywood to reduce weight. I would have loved to use acrylic so that the lights would be more visible from outside, but that was out of budget for this project! I cut 3 triangles out of each sheet of plywood using a track saw.
The LED strip is attached to the board using cable ties. The panels were too large for the laser cutter I had access to, so I laser cut templates that covered half of a panel and drilled holes for the ties manually.
Diffusion
A friend helped me sew together a fabric covering to diffuse the lights. The best method for doing this ended up being to hang sections in the dome itself and pin new triangles into place, before taking it down to sew them on.
Mapping and motion
I mapped the LEDs across the screen in Processing to create a 2D version. Anything I draw on the Processing canvas is repeated in realtime on the lights.
I worked with both a Kinect v1 and a Kinect v2 camera in different versions of this project.
The Kinect camera uses infrared to sense depth and I wrote software to detect differences over time in the depth readings, therefore detecting movement. Then I created visual effects that respond to this movement.
You can see some of the code on github.
Installation
I installed When in Dome at a variety of locations including gallery and festival settings. It took around 6 hours to build (for a fairly chilled experience) and around 1 hour to dismantle.
Press
When in Dome was featured in several online publications and my (ludicriously detailed) write-up on Instructables won first prize in a contest.
