Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!zaphod.mps.ohio-state.edu!rpi!batcomputer!andyrose From: andyrose@batcomputer.tn.cornell.edu (Andy Rose) Newsgroups: comp.graphics.visualization Subject: Crystal Eyes Message-ID: <1990Nov14.201940.23433@batcomputer.tn.cornell.edu> Date: 14 Nov 90 20:19:40 GMT Organization: Cornell Theory Center Lines: 46 Regarding C. Upson's call for wish list, any software which can drive the CrystalEyes setup or any other stereo pair setup would be great. When visualizing "regular" shapes in 3D, the spatial interpretation is helped greatly by the brain's ability to recognize straight lines and angles. As we begin to see more data which is amorphous, the lack of straight lines makes stereo viewing essential. For example, viewing a city street and discerning depth with one eye is not too tough since there are plenty of other visual cues, especially convergence of straight lines (perspective). Look at fire or a cloud with one eye though and there is little for the brain to "lock onto". Since a common viz technique is the display of particles (ex. 1000 small spheres animated), many of the tricks we have relied on in the past to fool the brain into "seeing" (feeling?) 3D don't work. Lighting models? Phong, Gouroud (sp), Blinn, Hall, ray trace, radiosity, whatever don't help because the surfaces are minimal and the balls may be moving quickly. Relative sizes (perspective transform) hardly helps unless you are right in the action. Shadows? Adding 1000 shadows on a flat surface behind the action will just confuse things. Reflections? Forget it. Visual occlusion (basic z-sort) and flat shading is fast and as good as more computationally extreme methods. However, if you have stereo vision (call it binocular disparity, or what you will) you "see" much better. A swirl of dots will jump out at you. Words, as usual, don't do justice to the effect so see it yourself. Because you can do much better with stereopairs than with all the fancy rendering stuff, it is more COST-EFFECTIVE to use your compute power to generate a left eye view and a right eye view in a simple model rather than a monocular view with all the bells and whistles. ... I heard (SIGGRAPH) that powerstation SGIs have been shipped with stereo ready monitors for some time now. I think that means they can display 120HZ. V for vis. -- Andrew Newkirk Rose '91 Department of Visualization CNSF/Theory Center 632 E & T Building, Hoy Road Ithaca, NY 14583 607 254 8686 andy@cornellf.tn.cornell.edu