Aspen Moviemap

Inhaltliche Beschreibung

MOVIEMAPS
Moviemaps allow virtual travel through pre-recorded spaces. Routes are pre-determined and filmed with a stop-frame camera triggered by distance rather than by time (typically done via an encoder on a wheel). Distance-triggering maintains constant speeds during playback at constant frame rates, which is often not practical or possible during production with a conventional (time-triggered) movie camera. The result, in a very real sense, is the transfer of speed control from the producer to the end-user, who has control over frame rate through an input device like a joystick or trackball.
In addition to speed control, limited control of direction is possible by filming registered turns at intersections. By match-cutting between a straight sequence and a turn sequence, the user can "move" from one route to another. Care must be taken to minimize visual discontinuities such as sun position and transient objects (e.g., cars and people). The goal is to make the cuts appear as seamless as possible.

FIRST INTERACTIVE MOVIEMAP
The first interactive moviemap was produced at MIT in the late 1970s of Aspen, Colorado. A gyroscopic stabilizer with 16mm stop-frame cameras was mounted on top of a camera car and a fifth wheel with an encoder triggered the cameras every 10 feet. Filming took place daily between 10 AM and 2 PM to minimize lighting discrepancies. The camera car carefully drove down the center of the street for registered match-cuts. In addition to the basic "travel" footage, panoramic camera experiments, thousands of still frames, audio, and data were collected. The playback system required several laserdisc players, a computer, and a touch screen display. Very wide-angle lenses were used for filming, and some attempts at orthoscopic playback were made. (see: R. Mohl, Cognitive Space in the Interactive Movie Map: An Investigation of Spatial Learning in Virtual Environments, PhD dissertation, Education and Media Technology, M.I.T., 1981.)
(M. Naimark)

Technische Beschreibung

Aspen Moviemap was developed at the Architecture Machine Group, MIT, funded by DARPA. The Goal was research into videodisc-based interactive video.

Innovative aspect of the project and research interest: novel method for audio-visual presence, multimedia.

Particular skills and resources necessary to realize the project: stop-frame, image stabilized, and panoramic cinematography, multimedia, and interface design.

Theorie / Forschung

Aspen Moviemap was one of the first interactive video projects ever. Seeded many others and in part led to the vision of the MIT Media Lab.
The Aspen Moviemap led to several moviemaps since.

FOLLOW-UP PROJECTS
The author has since conceived and directed several moviemap productions, each with its own unique playback configuration. The "Paris VideoPlan" (1986) was commissioned by the RATP (Paris Metro) to map the Madeleine district of Paris from the point-of-view of walking down the sidewalk. It was filmed with a stop-frame 35mm camera mounted on an electric cart, filming one frame every 2 meters. An encoder was attached to one of the cart's axles. Rather than filming all the turn possibilities at each intersection, a mime was employed to stand in each intersection and simply point in the possible turn directions. The idea was to substitute the perceptual continuity of actual match-cuts with cinematic continuity. The playback system was built in a kiosk and exhibited in the Madeleine Metro Station.

The "Golden Gate Videodisc Exhibit" (1987) was produced for San Francisco's Exploratorium as an aerial moviemap over a 10 by 10 mile grid of the Bay Area. It was filmed with a gyro-stabilized 35mm motion picture camera on a helicopter, which flew at a constant ground speed and altitude along one-mile grid lines determined by LORAN satellite navigation technology, effectively filming one frame every 30 feet. The camera was always pointed at the center of the Golden Gate Bridge, hence no turn sequences were necessary since the images always matched at each intersection regardless of travel direction. The playback system used a trackball to control both speed and direction, with the feel of "tight linkage" to the laserdiscs. The result was the sensation of moving smoothly over the Bay Area at speeds much faster than normal.

"VBK: A Moviemap of Karlsruhe" was commissioned by the Zentrum fur Kunst und Medientechnologie (ZKM). Karlsruhe, Germany, has a well-known tramway system, with over 100 kilometers of track snaking from the downtown pedestrian area out into the Black Forest. A 16mm stop-frame camera was mounted in front of a tram car and interfaced to the tram's odometer. Triggering was programmed to be at 2, 4, or 8 meter increments per frame depending on location. Filming on a track resulted in virtually perfect spatial registration. The playback system consisted of a pedestal with a throttle for speed control and 3 pushbuttons for choosing direction at intersections. The camera had a very wide-angle lens (85 degree horizontal FOV) and playback employed a 16 foot wide video projection. The input pedestal was strategically placed in front of the screen to achieve orthoscopically correct viewing, resulting in a strong sense of visual immersion.
(M. Naimark)

Veröffentlichungen

• M. Naimark, A 3D Moviemap and a 3D Panorama, SPIE Proceedings Vol. 3012, San Jose, 1997
  » http://www.naimark.n…t/writing/spie97.html [link 02]

Sekundärliteratur

• R. Mohl, Cognitive Space in the Interactive Movie Map: An Investigation of Spatial Learning in Virtual Environments, PhD dissertation, Education and Media Technology, M.I.T., 1981