From: Arnim Sauerbier (arnim@gene.med.umn.edu)
Date: Mon May 10 1993 - 19:29:24 UTC
Joerg Richard Weimar (jweimar@ulb.ac.be) wrote: : 3. If the camera is slightly rotated around he optical axis with respect : to the monitor, you get interesting effects, but this introduces a global : rotation, which is practically impossible to mimic with CA's (because : there is a global reference point) Yes, there are many interesting ways to adjust the parameters of the feed- back. Holding a mirror adjacent to the monitor so that the camera can see the monitor surface reflected in the mirror creates truly incredible patterns. I believe that the mirror combined with feedback creates multiple copies of ever-smaller screen-images, each copied recursively onto the final image with a fixed rotational offset and scaling factor. This is the video analogy of the famous "photocopier fractal" that one can generate by iteratively photoreducing and skewing an image drawn on paper. : To conclude: with a CA you could only mimic the experiments where all : controls are fixed and the camera doesn't do any automatic adjustments. : Also the camera needs to be aligned exactly with the monitor, and the : field of view must be exactly filled with the monitor. : I doubt that the patterns in this regime are as interesting as the ones : you get. Indeed, this is the problem, none of the Cellular-Automata algorithms I've seen take into account the position of the cell when computing its behavior. To trivially emulate video-feedback, perhaps one could simply recursively superimpose the original image onto the 'screen-space' with user-steerable skew, rotation, and magnification. To superimpose 100 copies of a 320x200 image, one would need approx 6,400,000 'superimposing-operations'. To do this at 30 times per second.... Wow. Anyone have a Cray to spare? _\\\/ ---------------------------------------------------------------------- = ..' Arnim Sauerbier "The United States constitution isn't per- C \) arnim@gene.med.umn.edu fect, but it's better than what we've got" \ - ----------------------------------------------------------------------
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