Chapter 4: A HISTORY OF COMPUTER ANIMATION ... - Vasulka.org

More documents

Recommendations

Info

Chapter 4: A HISTORY OF COMPUTER ANIMATION 3/20/92 32 programmed to follow the actions, such as walking, running, or spray painting . This is part of the promise of virtual reality . Benefits of Computerized Motion Control The introduction of a programming computer into the motion control complex accomplishes the same benefits as computerizing the animation stand : Analog recording media are replaced by digital ones . And the computer interface to the electric motor/shaft encoder commits one to programistic control . And herein lies an allegiance with the work of 3D graphics, CAD/CAM, robotics, and virtual reality . Aside from the repeatability and automation factors, the user may now direct the camera in terms of a language that describes the camera in a real-world manner and with real world terms . Another new advantage is that actions of the system, captured by the input mechanism and recorded, may now not only be played back, they may be edited also . It is also possible to elude either the input or output side of the full motion control model . For example one might employ a virtual camera and props to plan moves, and then use the motion control system to execute those moves with a real camera and props . Conversely, one might capture the parameters of a real camera move, and use those parameters to move a virtual camera . This is why the motion control paradigm is such a general purpose design (fig . 55) . 55 . Motion control paradigm crystalizes a general purpose input/record/process/replay/output model . The example depicts a camera with two degrees of freedom, pan and tilt, along with a prop to be photographed . During live action photography two shaft encoders transmit these angular variations to the CPU, which records them . In the diagram the two tracks are displayed on the computer's CRT display, along with the images seen by the camera . During replay these angular variations are dispatched back to stepping motors which pan and tilt the head, following the movements made during the live action as exactly as possible (or following whatever movements the animator gives them) . In practice the shooting camera and the replay camera may be identical or different . The computer system may also be equipted with a virtual camera and prop, the dimensions and linkages of which are identical to the real camera, this synthetic environment is show at the top, and the view of the synthetic camera is show on the right of the CRT display . A key idea is that both the real camera and the virtual camera are controlled and notationally mediated by a common, identical computer graphic language, and that the
Chapter 4 : A HISTORY OF COMPUTER ANIMATION 3/20/92 33 Synthetic Imagery Computer hardware fusions We now turn our attentions toward the evolution of animation based on synthetic imaging . In the beginning this was done with one of three technologies : the batch computer and the mechanical plotter, the batch computer and the CRT film recorder, or the the interactive refresh CRT . It was no until the 1980's that video became a viable method . The interactive cathode ray tube display Given the classical experiments with mechanical Lissajous figure drawing machines and the development of analog CRT oscilloscope graphics the connection of a CRT to a computer was a logical step for the pioneers . The first computer driven CRT seems to have been the Whirlwind I, built at MIT (1950), and which could display solutions to differential equations . One of the first computer animators, Dr. Ed Zajak of Bell Labs, wrote in 1968 that films were "known to have been made" on this machine in 1951, probably by filming real time off the face of the CRT, there is no surviving evidence that it was used to make animated films . [Well no, probably in the Computer Museum .] Computer driven CRTs were central to the purpose and design of the USAF SAGE computers built by IBM between 1952 and 1956 . In these applications a computer was used to integrate real time radar data from remote site locations and then position blips on the screen to correspond to the position of aircraft . Data about the aircraft's position was stored on a rotating magnetic drum which constrained the display list of all aircraft blips in a sector of airspace . The memory also contained attributes about the blip, or more precisely, about the aircraft, such as estimations of airspeed and fuel-the result of calculations between successive positions . Operators queried information about the blips using a light pen . The attribute data was displayed as alphanumeric text, and vector recording, editing (if any) of moves, and replaying of action is all relative to this script . At this level there is no difference to the animator whether the source of the script is real or synthetic, whether the output camera is real or synthetic, or whether source and the output are the same (real-real or synthetic-synthetic) or different (real-synthetic or synthetic-real) .
Page 1 and 2: tea:1 i20SZ bu :J1, Chapter 4 : A H
Page 3 and 4: Chapter 4 : A HISTORY OF COMPUTER A
Page 31 and 32: Chapter 4: A HISTORY OF COMPUTER AN
Page 33: Chapter 4 : A HISTORY OF COMPUTER A
Page 69: Chapter 4 : A HISTORY OF COMPUTER A

Chapter 4: A HISTORY OF COMPUTER ANIMATION ... - Vasulka.org

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?