Path: chuka.playstation.co.uk!news From: James Shaughnessy Newsgroups: scee.yaroze.programming.3d_graphics Subject: Re: Rotating about an arbitrary axis? Date: Fri, 18 Sep 1998 20:01:32 +0100 Organization: PlayStation Net Yaroze (SCEE) Lines: 35 Message-ID: <3602AE0C.5F9D@manc.u-net.com> References: <36028A8D.290E@manc.u-net.com> <36028CB6.F017A2D5@scee.sony.co.uk> Reply-To: james@manc.u-net.com NNTP-Posting-Host: manc.u-net.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 3.0 (Win95; I) James Russell wrote: > Use RotMatrixX(RollAmount) followed by RotMatrixY(CompassDirection) Ooo excellent, cheers! I'm unfamiliar with those functions so I've got some reading/experimentation to do. > Secondly, just an observation... Why are you using 3D for the balls? > Wouldn't sprites be faster? Yes they HAVE to be real spheres :-) The main reason is bitmap sheres may look good for stills but regarding the game of pool, where they have numbers (er and Spots and Stripes of course) and need to roll and spin realistically it's MUCH nicer looking to see real-time gouraud-textured spheres. they are only 128 polys each and there's only ten balls on the table so I should still easily get it running in 50fps even at 640x256 medres. You'll see when I upload an early demo. It's currently going around 250 HSyncs with loads of CPU wait-time, for all those pending maths calculations. I want it to feel as good as Virtual Pool which was near perfect so they'll be a LOT of maths to sort out.. Scaling bitmaps with a pseudo-textured-roll effect would just look terrible without using some fancy textures-on-a-sphere algorithm (like in Virtual Pool) totally defeating the object.. and there's not enough framebuffer to have massive maps of prerendered balls from all angles. Trust me it should look pretty cool, even if it plays like a dog ;) Thanks again, Jim -- ----------------------------------------- James Shaughnessy james@manc.u-net.com http://www.netyaroze-europe.com/~shaughnj -----------------------------------------