Path: utzoo!censor!jeff From: jeff@censor.UUCP (Jeff Hunter) Newsgroups: comp.graphics Subject: Re: 3-D perceptual abilities Summary: weird but tiring Message-ID: <390@censor.UUCP> Date: 7 Mar 89 05:38:48 GMT References: <2493@masada.cs.swarthmore.edu>, Organization: Bell Canada, Business Development, Toronto Lines: 36 In article , po0o+@andrew.cmu.edu (Paul Andrew Olbrich) writes: > Patrick Farrell writes: > > Here is an interesting thought. If there were no shadows everything > > would look completely flat. Anybody agree or disagree with > > that statement? > Better yet, wouldn't everything look wierd if we didn't get gray shade input? > (That is, only information like "this is red," and "this is greenish-blue.") > And everything was the same level of brightness. No shadows here, and walking > through unlit rooms would be easy. Everything would have pretty much of a fake > appearance. (Yessir, I'm a wierd one ...) > Have you ever seen those op-art pictures where there is bright blue lettering on a red background and the edges flicker badly enough to make your head ache? A recent Sci. Am. said the effect is due to the split in the brain between the black-and-white vision system, and the colour one. The B&W is used to pick out the edges of the scene, and the other picks out blobs of colour in somewhat less detail. The two visions are combined in somewhat the same manner as a colouring book. The trouble comes when two colours are picked that reflect almost exactly the same amount of light. The B&W system just sees a uniform grey. The colour system spots an edge (between the two colours) and asks the B&W to find it.... Your eyes and brain continue to oscillate until you look away. I'll agree that walking thru unlit rooms would be easy, but keep your eyes shut tight in the sunshine! :-) > "Because cows have a complex four-stomach digestive system, they are technically > incapable of vomiting as we know it." ... and if they have "gassid indigestion" they can die from it. A pretty high price for the ability to eat lawns.... -- ___ __ __ {utzoo,lsuc}!censor!jeff (416-595-2705) / / /) / ) -- my opinions -- -/ _ -/- /- The first cup of coffee recapitulates phylogeny... (__/ (/_/ _/_ Barry Workman