- by Chris Wood
in Answer Box
One lighting designer leaned in pixel-mapping and new technology to make a brand new Christmas Angel
The musical Rent, as with all industry changing productions, has earned iconic characters and popular moments for which audiences have developed firm expectations. At the University of Northern Iowa, director Jay Edelnant, costume designer Amy S. RohrBerg, and I (lighting designer) wanted to break those expectations. The character Angel Dumott Schunard is traditionally introduced in a Santa Claus costume for the musical number “Today 4 You.” Our costume designer wanted to break with tradition and have Angel enter dressed as a Christmas Tree. As a lighting designer, one instinct is to offer Christmas tree lights as an option, but I wanted something new. So the decision was made to pixel map on the dress. When pixel mapping, you have individual control over each LED pixel in the dress as opposed to LED strips where the set of LEDs are controlled as a whole. The goal was to make the LEDs in Angel’s dress look like regular Christmas tree lights upon entering. As "Today 4 You" started, we could chase across her dress, show animations, and strobe, enhancing the exotic and creative personality of Angel.
Initially we thought about using a Flora Arduino card to control the LEDs but quickly realized that would not be feasible during technical rehearsals. If we wanted to alter the look, we would have to input the code on our laptops and reload it onto the controller. After contacting RC4 Wireless for help, we became the beta testers for their new DMXpix Dual String Pixel Mapping Unit. This allowed us to control, edit, and create the pixel mapping content in real time through the ETC EOS pixel mapping software. The DMXpix and the EOS software saved us a tremendous amount of time in an already shortened tech process.
The pixel mapping LEDs came from AdaFruit. We chose the NEO Pixels to allow for an even dispersal across the dress without looking too regulated. The data and power lines were initially sewn to the costume using heavy gauge steel thread allowing for the fabric to hang more naturally than had we used insulated cabling. There were three lines of running stitches connecting the NEO pixels: one from each of their data points, one running along the ground line and a central stitch connecting the power. They then linked to the pixel driver located in a pocket at the back of the dress. While this pocket was made from the same dress fabric and was low profile, the design had a bolero jacket overtop, which made hiding the RC4’s tiny 3-inch-by-1-inch-by-1-inch pixel driver and the flat 3-inch-by-3-inch-by-1/2-inch battery pack much easier.
Upon our first test run we discovered that of the 64 NEO pixels, only the first 10 turned on. After some research, we found that the dress fabric had metallic threads woven through it and was dissipating our voltage. We had to make the switch to insulated pixel mapping ribbon to protect the LEDs from the dress. This ribbon was sewn to the dress with silamide thread in a catchstitch, allowing for both movement and security.
Four AA rechargeable alkaline batteries were chosen to power the LEDs and the DMXpix unit. The rechargeable AA batteries gave us a longer running time than regular batteries, coming in at 2700 mAh. We choose to use alkaline batteries to save on cost.
When working with pixel mapping you have to keep in mind your data structure. One RGB pixel will take 3 channels to control it. The dress had 64 pixels that added up to 192 control channels. We had the option of adding more pixels but our already tight data structure could not support it. The DMXpix can group pixels by reducing the number of control channels required, but in our situation we needed to control each pixel individually.
The Angel dress brought a fresh take to Rent and was a prime example of a successful collaboration between the lighting team, costuming team, and the artist performing on stage. This was a fantastic learning experience for the students and designers. It cannot be stressed enough how important prototyping and mock-ups are when trying something new in your theatre. It was a pleasure to be one of the first people to use RC4 Wireless’ DMXpix in a production and discover new ways to utilize it.