On Mon, July 18, 2005 4:26 pm, Miguel said: > > ... educate me ... :-)
OK, you asked :-) More years ago than I want to consider I was doing some research and came across a paper by J.T. Rule titled "Stereoscopic Drawings" (J.O.S.A., 1938) in which he discusses the underlying inadequacies of using monocular projection methods to simulate stereoscopic vision. His methodology isn't directly applicable to the computer screen because it relies on using a proper lens- or mirror-based stereoscope. Nevertheless it does lead to the concept of "asymmetric frustrum projection" as the mathematical method of choice to create a projected image that is both geometrically correct and pleasing to look at if you do not use a mechanical stereoscope to view the images. While the actual equations for calculating the right and left projections are very simple the choice of parameters is dependent on how the images are to be rendered, e.g. as side-by-side for viewing with unaided eyes or as alternating images viewed using synchronized-shutter glasses. This is the "art" part of creating an image that isn't a strain to view and is somewhat dependent on the person doing the viewing (which is why I like to suggest that the parameters are user-accessible). I implemented this method as an exercise to compare it to the standard of the day (rotation-based projections viewed using a mechanical stereoscope) and the early non-stereo interactive computer-graphics. The performance penalty wasn't that great and, to me, the images were easier to view for extended periods of time (especially when trying to keep the edges of the image in full stereo). Rather than reproduce the full details of the calculations and implementation here I'll refer you to two of the pdf's at the www.stereographics web site: 1) pages 4-9 of HPsdk (http://www.stereographics.com/x_downloads/developers/hpsdk.doc) 2) chapter 6 of the Stereographics delveloper's handbook (http://www.stereographics.com/support/downloads_support/handbook.pdf) The rest of both of these resources has a lot of useful information as well. Rich ------------------------------------------------------- SF.Net email is sponsored by: Discover Easy Linux Migration Strategies from IBM. Find simple to follow Roadmaps, straightforward articles, informative Webcasts and more! Get everything you need to get up to speed, fast. http://ads.osdn.com/?ad_id=7477&alloc_id=16492&op=click _______________________________________________ Jmol-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/jmol-users
