Path: chuka.playstation.co.uk!news From: Jim Newsgroups: scee.yaroze.programming.3d_graphics Subject: Re: Light Sources Date: Tue, 22 Apr 1997 00:25:51 +0100 Organization: PlayStation Net Yaroze (SCEE) Lines: 35 Message-ID: <335BF77F.251E@micronetics.com> References: <335B6F68.7441@aisb.ed.ac.uk> <335db17a.5478878@news.playstation.co.uk> NNTP-Posting-Host: jim.micronetics.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 4.0b2 (Win95; I) X-Priority: 3 (Normal) Alex Amsel wrote: > > On Mon, 21 Apr 1997 14:45:12 +0100, Gordon Bell > did quoth at me: > > As far as I know the PS-X only handles 3 sources in hardware. I'm just guessing but I don't think the psx has any hardware lightsourcing built in. Just the calculations are handled by the gte. The 3 light source limit is a limitation imposed by Gs. >They take account only of direction and NOT distance. Yes it not a full implementation of Lamberts laws. >With the full libs > you could probably use matrix calcs etc to do light sourcing in > software, and gs has structures allowing you to set the rgb values on > a per vertex basis, although its internal lighting calcs will then > have no effect. This is essentially what Gslib does. I think its only limited to 3 light source for performance reasons. Considering it has to dot each normal and light vector, this is quite reasonable. I guess you could frig lighting by setting ambient lighting on by default and modifying the gradation rgb structures directly in the tmd Regards Jim