Newsgroups: comp.graphics Path: utzoo!utgpu!jarvis.csri.toronto.edu!dgp.toronto.edu!elf From: elf@dgp.toronto.edu (Eugene Fiume) Subject: Re: raytracing in || (supersampling speedup) Message-ID: <8811301336.AA04765@explorer.dgp.toronto.edu> Keywords: 4 rays per pixel Organization: University of Toronto, CSRI References: <9700001@datacube> <3148@uoregon.uoregon.edu> <1351@umbc3.UMD.EDU> <5263@cbmvax.UUCP> <5548@thorin.cs.unc.edu> <7034@watcgl.waterloo.edu> Date: Wed, 30 Nov 88 08:36:27 EST In article <7034@watcgl.waterloo.edu> awpaeth@watcgl.waterloo.edu (Alan Wm Paeth) writes: > >The technique used by Sweeney in 1984 (while here at Waterloo) compares the four >pixel-corner rays and if they are not in close agreement subdivides the pixel. >The recursion terminates either when the rays from the subpixel's corners are >in close agreement or when some max depth is reached. The subpixel values are >averaged to form the parent pixel intensity (though a more general convolution >could be used in gathering up the subpieces). This technique was, of course, mentioned in Whitted's 1980 paper. -- Eugene Fiume Dynamic Graphics Project University of Toronto elf@dgp.utoronto (BITNET); elf@dgp.toronto.edu (CSNET/UUCP)