Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!zaphod.mps.ohio-state.edu!rpi!masscomp!calvin!mark From: mark@calvin..westford.ccur.com (Mark Thompson) Newsgroups: comp.graphics Subject: Re: "VIDEO THING" video converter for PCs ... Message-ID: <61631@masscomp.ccur.com> Date: 17 Jan 91 16:31:07 GMT References: <1991Jan14.054313.24338@mintaka.lcs.mit.edu> <8164@ucdavis.ucdavis.edu> Sender: news@masscomp.ccur.com Reply-To: mark@calvin.westford.ccur.com (Mark Thompson) Organization: Concurrent Computer Corp. Westford MA. Lines: 30 In article <8164@ucdavis.ucdavis.edu> zerkle@iris.ucdavis.edu (Dan Zerkle) writes: >> This spectacular device is called the Video Toaster from NewTek. Its >[stuff deleted] >>LightWave3d modeler/ray-tracer, ToasterPaint, a production level switcher, >[yet more stuff deleted] > >I would guess that you >can get pretty much the same sort of pictures that a ray tracer would >give you, but without reflections or refractions. The ordinary Phong >system doesn't usually give you shadows, but I remember seeing them on >a Toaster picture, so LightWave probably does something clever like a >double visible surface algorithm to get them. Lightwave is an outstanding Phong renderer that made me say good riddance to ray-tracers. I'm not sure which shadowing algorithm is used but I don't believe it is a depth buffer. I think I recall mention that it used ray-casting but I am not certain. Anyway, I might mention that shadow support has been improved with latest release of the software (rev 1.0). You may now select shadowing on an object basis rather than just for the entire scene. For each object you can select any of the following: 1) receive shadow, 2) cast shadow, and 3) self shadow. This kind of control can dramitically improve shadow rendering time. %~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~% % ` ' Mark Thompson % % --==* RADIANT *==-- mark@westford.ccur.com % % ' Image ` ...!{decvax,uunet}!masscomp!mark % % Productions (508)392-2480 (603)424-1829 % % % ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~