A closer look at the hardware used to make BodyLapse
What started as a small project in a cyber art class has evolved into a comprehensive program for Charles Wood, the creator of BodyLapse and a 2008 Virginia Tech alumnus. The listing below details the different pieces of hardware used to keep track of Wood's fitness progress.
The motion control rig
To capture a number of body motions from several different angles, a rig capable of positioning itself was needed. Motion control cameras, which have been used for decades in the film industry, were researched, and a simple rig was designed to move the camera on three axes: dolly, pan, and tilt. The track of the camera system consists of a 12-foot length of aluminum ladder, and two sawhorses built in Virginia Tech's architecture lab. The sawhorses are bolted to the stage floor and have two sets of inlaid bolts, both in the base and across the top beam. This allows a track to be placed at either the floor or waist level. These sets of bolts guide and lock the system for positioning a track. The ladder was selected for its low cost, high rigidity, and its manufactured sides that include a cusp for the dolly wheels to grip easily.
- The dolly
The dolly that rides along the track is home to the Pan/Tilt Head. Constructed like a catamaran, it consists of two aluminum wheel trucks, and an aluminum cross member that seats the Pan/Tilt Head. This “H” type construction allows for the wheel trucks to adjust to different size ladders, and also provide maximum stability.
- Pan/tilt head
The Pan/Tilt Head is a 22-pound motor-driven unit that was lent to the BodyLapse project. The head itself uses a ball-bearing construction for the motion, and is attached to the dolly via special aluminum mounts that were built at Virginia Tech.
- The Kuper computer
To drive the motion of the rig, Bill Tondreau's Academy-Award winning Kuper Motion Cards and Kuper Software are used with a standard servo driver box for control. The Kuper software and cards allow up to 48 axes of control. The software allows Wood and his team to program all the camera moves for the animations, and play them back repeatedly over time.
- The HD camera
The Panasonic AGHVX200 records to a memory card system. The camera was selected for its ability to record at 60 frames per second at a resolution of 1280 x 720 pixels.
BodyLapse is being shot in Newport, Va. The studio space is approximately 22 feet by 25 feet. A black backdrop was constructed from nine black bed sheets.
Wood purchased used lighting instruments for the duration of the project. The lighting setup consists of several homemade elements with products from local craft and hardware stores.
In order to control the camera's position for every recording, an optical alignment method was implemented. Using two charts (one for the upper level of track, the other for the lower) with converging shapes and lines, the camera is dollied to a point on the track, the focal length is set, and the camera is pointed at the alignment chart. Using a video feed from the camera to a computer, the image is aligned with a reference image that was taken on the first day of shooting. The two images are overlaid using software, and the home state is set in the Kuper Computer system.
Digital capture process
Every three days several camera passes are shot of every animation to document increasing weight loss and muscle gain. The motion control camera rig is positioned for each animation, and using the same alignment software that is used to align the camera. Wood positions his body in certain poses to make sure he is in the correct position.
The footage that is generated from the camera usually yields two gigabytes per pass, per animation. All the footage is recorded directly from the camera, through the computer, onto a one terrabyte external hard drive. Weekly backups are made to another hard drive.