Path: chuka.playstation.co.uk!news From: Developer Support Newsgroups: scee.yaroze.programming.3d_graphics Subject: Re: Help: GsSortObject4 & GsSortOT Date: Wed, 22 Oct 1997 17:30:07 +0100 Organization: PlayStation Net Yaroze (SCEE) Lines: 40 Message-ID: <344E2A0F.15B5@interactive.sony.com> References: <344e12ea.11334163@news.playstation.co.uk> NNTP-Posting-Host: 194.203.13.10 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 3.01 (Win95; I) To: alex@teeth.demon.co.uk > Problem 1: Some docs claim GsOT.offset works and some claim it > doesn't. What is the truth?! It would be 'rather' useful! No, it doesn't work. The field exists for future implementation. > Problem 2: The serious one. I'm inserting my little OT fine, and it > inserts it according to GsOT.point. Presumably point should be Z >> > OT_SHIFT where OT_SHIFT is your shift value for the main OT, and Z is > approximately the distance from the object to the camera. > > In my case my main scene is rendered into the main OT with a shift > value of 3. My scene goes from approx -8000 -> +8000, so I currently > have an OT of length 11. This should work fine, although as I said in > another posting, when things should have gone flying off the OT it > didn't seem to get bothered. > > I have found reasonable values for GsOT.point but they seem to be 100% > unrelated to the distance of the object in question from my camera > (including when allowing for shifts etc.). For the record the value > that works is approx 15 while the value I expect it to be is either > 600 or 75 (depends if you account for shifts). Very approx figures. > > Either GsSortOT is getting annoyed or possibly my main rendering code > is somehow squeezing Z values down far more than I want it to. > > Any solutions? Kinda urgent! Please reply personally as well as on > here if possible. > > I've probably got a really silly mistake somewhere that I'm blind to. > You know how it is. The worlds 16bit, I take it 600 is the distance you want the small OT from the viewpoint, and the large OT is 11bit. So 600/(65536/2048) = 18.75 the value to include the little OT at. Gs divides the entire 16bit world into sections for the OT, so each OT section in your case is 32 wide. The start and end of the the objects within the world makes no difference at all. Stuart