Path: chuka.playstation.co.uk!news From: Developer Support Newsgroups: scee.yaroze.programming.3d_graphics Subject: Re: General 3d Questions. Date: Thu, 29 May 1997 17:00:32 +0100 Organization: Sony Computer Entertainment Europe Lines: 93 Message-ID: <338DA820.77FB@interactive.sony.com> References: <338CF88E.2608@cobradev.demon.co.uk> Reply-To: N/A-Use-Newsgroup 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) colin adams wrote: > > Hello All > > This is not A Tech support Question, But You can > Answer if you wish & I would be very Grateful. > > I wonder if Anyone could enlighten me on a few Questions > that have recently been Nagging my Overloaded Grey Matter. > But first some background info. > > I am currently working on a Map Editor for a 3d World. > The World Objects (WO) (Only Floors & Walls supported at > present) are made up of Textured Quads (at last I sussed it):-). > The Objects are initially placed in the World via translation. > The World is currently scrolled around in 8 directions by > modifying the x y z positions of the Objects. > At present The Game engine could support a game like > "Crash Bandicoot" or "Lone Soldier". i.e. (the world doesn't > rotate in the direction of the viewpoint of the player character (PC) ) > before I begin building functions around this rather limited engine > I would like to ask a few questions. > > 1. When coding a game of this type is it best to-: > (a) Scroll the WO & leave the PC x y z co-ords alone ? > (b) Move the PC & Viewpoint & leave the WO xyz co-ords alone? > At present I use (a). > What really turns on the difference? Without knowing anything about your engine, it is generally easier and quicker to move a single camera (just setting the view, i.e. determine the world <-> screen matrix) than to move the whole world, but the difference is often not very pronounced. > 2. How do games like Tomb Raider Doom ect Rotate the world in the > direction > of the PCs view point? > a) Rotate the WO in relation to the position within it? > b) Clever use of camera Angles? > c) Both? > d) put your $2 worth here > As (1) above, you can do it either way. See the <3d6> sample for various view modes, which come out of various simple but powerful ways to move and rotate the camera. Vital things to do with a camera: (1) be able to move and rotate in many ways to create a nice variety of view modes e.g. attach to object for over-the-shoulder or immersive/local view. (2) find its matrix: the position, direction and orientation of the view > 3. Z buffering Has any one any good algorithms for this? > Haven't used Z buffering, but there are lots of newsgroups on the web that discuss 3d graphics, and numerous books, articles, magazines, etc. I'm not convinced about its applicability on Yaroze since Z buffering is generally a computationally expensive process that the PSX hardware does not support; doing it all via CPU would probably be severely punishing on frame rate. > 4. Could anyone point me in the direction of any specific Net Resources > i.e. FAQs, WWW, FTP ect that explain any of the Above? > I can suggest the obvious: net searches, look for newsgroups. > 5. Can Yaroze Handle a game of this Type? > In a word, yes. The Yaroze hardware is essentially the same as that of the consumer PlayStation; while the Yaroze libraries may be a little slower, this difference is too small to qualify as anything but a bad excuse for not doing good games. > I am aware that many of these Questions may be asking for a little to > much > info But if you don't Ask, You wont get any Answers. > > Thanks in Advance > > -- > Cobra