Projection Mapping – ArtsFest 2013

I was supposed to upload this about a month ago – priorities I suppose…

I started looking at projection mapping three years ago (at least) and have wanted to get something going on my own. A UCA summer grant helped me get going by doing some research on mapping options and proposing a demonstration project. Unfortunately, Europa took a lot longer to finish than expected so it pushed the implementation of the projection mapping project down the road.

In the fall of 2012 I started designing a set to project onto. I limited the set to cardboard boxes I could buy at Lowe’s to keep it simple and keep my costs down. After seeing several box-based sets online, I came up with some specifications:

  • Boxes should be at 45 degrees or perpendicular to the projector so an equal number of pixels could illuminate each surface
  • Be interesting looking – stay away from bilateral symmetry (no pyramids)
  • Be 8 feet or less across and fit within a 4:3 aspect ratio (to fit the projector’s output)
  • Minimize shadows cast from one box to another

Once the design was done I built it in a room in Stanley Russ Hall using 19 boxes that were three different sizes. I then setup the projector and projected the virtual model of the set onto the real set and adjusted both as needed. It was at this point that I made a fundamental mistake that I need to fix as soon as I have time. I got fixated on the idea that the virtual camera should be in the same place as the projector relative to the set. That was dumb. Projectors are designed to shift their images so they can be placed on ceilings or table tops. The center of the projected image does not align with the lens placement in a room. A camera typically does not shift like that, but I somehow forced the camera alignment to work laying on the ground. For most of the imagery it works fine, but when I started designing imagery that looked inside the boxes the whole effect broke. It wasn’t until about a day before my deadline that I realized the problem. It is an easy fix, but requires that I re-render most of the animations, which will take a few days. You will see the problem particularly in the second-to-last animation where the boxes open up.

The project was very well received at ArtsFest. I talked to a lot of people about how it was done and I got great feedback on what people liked the most. Interestingly, the first animation I did ended up being the favorite of most of the people I talked to. It is the one that several people described as being like speakers pulsating. The grid animation got several oohs and ahhs, which made me laugh because it was the last animation and the simplest to do. My favorite is the spotlights. Besides the look, it was cool to hear people arguing about whether there were more real objects on the boxes and several adults and children got up close to the boxes to make sure there wasn’t more to them.

The next projection mapping project for me will have realtime graphics – imagery that is drawing on-the-fly rather than video files. Realtime graphics can respond to stimuli, such as human motion, light, and sound. I’m currently working out my programming muscles that had atrophied so I can pull off something more interesting than this first project.