Path: chuka.playstation.co.uk!news From: "Tom" Newsgroups: scea.yaroze.programming.3d_graphics,scee.yaroze.programming.3d_graphics Subject: Re: 3D Splines Date: Thu, 4 Nov 1999 21:46:15 -0800 Organization: PlayStation Net Yaroze (SCEE) Lines: 26 Message-ID: <7vsup4$3c61@chuka.playstation.co.uk> References: <381FAE75.BD3A3572@surfsouth.com> NNTP-Posting-Host: asn1-166.mcmail.com X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 5.00.2014.211 X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2014.211 Xref: chuka.playstation.co.uk scea.yaroze.programming.3d_graphics:383 scee.yaroze.programming.3d_graphics:1427 Hi there, I don't know if you're on about my racing game or not (the one with untextured buildings and reflection mapped hovercraft), but I'll tell you how I did the track design anyway. Each segment on the track has three variables associated with it which control its orientation relative to the previous segment. The first is the angle left / right which is used not surprisingly to control the tighness of each corner. The other two control the height of the left and right edges of the segment relative to the previous edge. Thus if one is greater than the other, the track will begin to bank and if they are both the same, the track will form a hill. It's pretty difficult to explain, and I'm not the best person in the world at explaining things (it once took me four e-mails to explain the difference between a pointer and a variable to someone). I did splines once long, long ago when I had an Acorn (used to texture the winning tunnel challenge entry, Acorn User fans) but unfortunately I no longer have the source code. I do remember that I spent a good afternoon trying to solve simulatious equations with four unknowns with only a GSCE level knowledge of maths. Ouch! Cheers, Tom