Budapest Régiségei 41. (2007)

MŰEMLÉKVÉDELEM, ADATTÁRAK - SZENTGÁLI Ádám: Kronoszkóp - ablak a múltra

CHRONOSCOP - WINDOW TO THE PAST The Computer and Automation Research Institute of the Hungarian Academy of Sciences (SZTAKI) has developed a "looking-into-the-past" mechanism for the Aquincum Museum, a branch of the Budapest Historical Museum. Across a rotating telescope standing on a pedestal, the visitors can gaze at computer reconstructions of the ancient buildings. The SZTAKI used the instruments used in virtual reality and built these into the mechanism standing in the archaeological park running along Szentendrei Road. So it is enough for visitors to stand in front of that chronoscope, located strategically among the ancient monuments, and gaze into it. The visitors can pan around in along horizontal plane with the window standing on a pedestal and look at everything of interest to them. The scenery is hard to put into words. The past and the present and the idea and the reality are inter-twined on the three dimensional picture. One part of the picture is original: the environment of the ruins area, its streets and its trees. The 2000 year old computer reconstructed buildings stand on the places of the more important wall remains and foundations. Reality is amplified because the sky is cloudy or the sun is shining in the viewer as outside in real time. The virtual buildings cast shadows on each other and their surroundings. This is very important because the audience sees everything together. The virtual picture itself lies in the middle of the field of vision but it is possible to look out the side and below the housing of the machine. Thus, the reality follows the virtual picture but is enhanced by the reconstructed buildings. Through a grant from the National Cultural Foundation, SZTAKI and the American Silicon Graphics' advocacy in Hungary got the chance to develop this system further. As the first step, the director of the museum decided to install two "looking-into-the past" mechanisms. One of them is placed next to the old main museum building where the Great Public Bath, the old Roman market and the nearby artisans' houses can be clearly seen. The other is placed near the new open-air theater where a virtual reconstruction of the Great Dwelling House and the so-called long house covering the Mithras shrine can be presented. The reconstructed buildings are photo-real, with the form of their walls, roof constructions, windows and doors of the original buildings based precisely on what is known today about the original edifices. The chronoscope itself comprises a metal tube frame, a robust mechanism designed to withstand damage. As it stands open to the elements, it has to be able to stand serious strain. The stainless steel housing closes hermetically against the wet and on sunny summer days, the built-in cryogenic system switches on. The most important thing, the video picture visualizing unit, is in the head part. It can be used through two viewing openings. The height of the head part can be moved up and down like a telescope so children and people in wheel-chairs can use it. The horizontal viewing angle of picture visitors see is almost thirty degrees. The curved scanning angle widens the view further. The chronoscope can be rotated 150 degree - to impact - using the handles situated on the two sides of the stand. Software is used to take the picture and combine it with the video techniques - a methodology never before attempted in computer studies. The computer itself naturally sits in a protected place - in the old museum building while underground cables connect it with the chronoscope itself. The based idea came from Ádám Szentgáli who headed thelandscape Informatics Department of the Automation Research Institute of the Hungarian Academy of Sciences. His colleagues guarantee continuity in the project under leadership of László Holakovszky who planned the most complicated part of the project, the picture visualizing and lighting system. Dr. Gyula Istvánfi, professor emeritus in the Department of History of Architecture and Monuments at the Budapest University of Technology and Economics developed the theoretical schémas. Dr. Paula Zsidi, director of the Aquincum Museum, kept checked on the archaeological authenticity. The models-in-space saw the light at the Department of Architectural Representation. A computer graphics organization (COMPulz Bt.) placed these models within the modeled environment of the ruins area and produced the visualizing reality from them. The Space Physics Institute (Légkörfizikai Intézet) guaranteed the sidereal algorithm the sun's orbit across the sky in order to properly simulate the light and shadow