Re: reference library design/mdl file formats

Bernd Kreimeier (Bernd.Kreimeier@NeRo.Uni-Bonn.DE)
Wed, 6 Mar 1996 13:55:32 +0100 (MET)

From: Bernd Kreimeier <Bernd.Kreimeier@NeRo.Uni-Bonn.DE>
Date: Wed, 6 Mar 1996 13:55:32 +0100 (MET)
Message-Id: <>
Subject: Re: reference library design/mdl file formats

>> warning on still changing file formats

> This is the reason why I write QEU as a library of generic routines
> for loading and saving files. If anyone uses this library for a
> program, it will be easy to upgrade to any new format, because only a
> few things will have to be changed in the library and most of the

There are two important aspects to remember in designing a portable
reference library for QUE and other tools:

a) keep in mind the interactive editing specific needs for
Constructive Solid Geometry-compliant data structures.
This too will be worth the additional work in the end.
I recommend looking at the references given on the
"recommended readings" page (see below): the books
by Martti Mantyla and Ian Ashdown, in particular,
featuring half edge representations.

b) keep in mind the specific needs involved with near-realtime
rendering. We might or might not succeed in writing some
(even non-texturing) 3D preview this time, but you definitely
won't be able to integrate any such beast with a modeller/editor
as long as your data structures are focused on being dynamically
only (adding/removing vertices etc.), without taking
efficiency into account.

Two additional remarks: for radiosity-style calculation of lighting/shadow
maps, I definitely recommend taking a close look at the HELIOS sources that
are now publically available, written by Ian Ashdown. As for slow but
doable 3D preview, I recommend looking at the Mesa library. Both referenced
on the "overview of resources" page, which, like "recommended readings", is
cross-referenced now at

the Quake Developers Support pages.