Subj : Re: Rational Trig To : comp.programming From : Gerry Quinn Date : Sun Sep 18 2005 12:48 pm In article <5bb70$432d3850$50397e1f$15305@news.chello.nl>, jongware@post.in.group.plz says... > "DarkD" wrote in message > news:432d060f$0$22741$afc38c87@news.optusnet.com.au... > > How big an impact do you think rational trig will have on future coding of > > 3d games, particaulalry because any use of the inifinte sin cos series is > > now redudant and not needed. hardware trig calculators that don't involve > > recurssion or lookup tables? > > http://web.maths.unsw.edu.au.nyud.net:8090/~norman/papers/Chapter1.pdf I am unconvinced that recursion and look-up tables are to be avoided simply by replacing distances by their squares, and angles by the squares of their sins. Aren't we going to need them to get from quadratures to distances, in any case? Distances are not going to go away as a commonly desired result from calculations. I don't care what the hardware does. All I care is what is easiest for *my* calculations / formulae. Again, I have my doubts whether there is much benefit. > What an interesting read... As --most probably-- all of you I grew up with > circles and arcs, and after many, many years I finally can use them in > programming. A quick once-over of this story and I already feel at home ... > Though, just as _any_ alternative technique, general acceptance might not > ever occur. There are so many 'better' techniques which disappeared for > reasons not always obvious. VHS, Betamax -- you know the story. BTW my next > 3d program will most likely use sine lookup tables -- again! I'm just too > damn lazy to learn basic math again. Angles and their trig functions work well for most 2D problems - the harder geometry problems are in 3D. If 'rational geometry' simplifies 3D calculations, it might catch on. - Gerry Quinn .