Re: My Quake Editor

John B. Williston (
Wed, 26 Jun 1996 15:16:52 +0000

Date: Wed, 26 Jun 1996 15:16:52 +0000
From: "John B. Williston" <>
Subject: Re: My Quake Editor

Chris Cason wrote:
> > Could you summarize the major design differences of Direct3D vs.
> > OpenGL? I've always wondered (having no access to Direct*), and
> > this would certainly be valuable info.
> I second this - I'm having trouble deciding between the two myself. I've
> tried hunting around but didn't find much of substance at the time I looked.
> I'd appreciate some sort of comparison (or a pointer to one.)

Let me toss my brief 0.02 in here. OpenGL is a well-defined set of API's that is
available on many platforms. However, as is seemingly the case with virtually all
Unix-originated technologies, it is clearly something that accreted over time. I.E. I
find the API to have a "designed by committee" look and feel.

On Windows/NT, OpenGL performance is acceptable for moderately complex scenes; on my
P120 w/32 MB RAM very complex scenes bog down pretty badly. Under Windows95, the
performance stinks at present until Microsoft marries OpenGL to DirectDraw. I created
a quick little example that simply rotates a multi-colored cube in each window; under
WindowsNT 8 separate windows looked great, whereas under Windows95 the animation was
quite jerky with only 2 windows open.

Direct3D is one of the DirectX technologies. It is built upon the COM foundation used
by OLE at the heart of Windows95. While some of its conventions are a bit strange for
those familiar with 3D programming, it is pretty simple to use once you get the hang
of it. The biggest endorsements for Direct3D, IMO, are:

1) It's built on DirectDraw, thus inheriting the custom drivers that take advantage of
accelerated video cards.
2) It will be built right into the operating system.
3) It supplies high and low level API's to work with primitives or complete 3D objects
as needed.
4) It has good support for user interaction with a scene; I had a difficult time
getting this to work under OpenGL, although I will admit this might be due to a lack
of OpenGL knowledge on my part.

In the last four or five months of QuakeAuthor research, I've learned a great deal
about OpenGL vs. Direct3D. At one point, I was even considering doing my own 3D
engine, but I suspect no matter what I do Direct3D will always be faster.


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