QD3d, RAVE, & Hardware

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David Gabriel White

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Dec 20, 1996, 3:00:00 AM12/20/96
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I decided to poke around a little and see what I could find out
about QuickDraw 3d, RAVE, and hardware accellerators. I'm posting this
in hopes that someone can tell me if I'm understanding this correctly,
or possibly elaborate on the subject.

I was trying to find out what differences there are between Apple's
QD3d card and other companies' cards (XClaim VR or 3d). The primary
function I'd wand out of the card would be to aid in creating 3d
animations. My main interest in Apple's card comes from the fact that I
already have a good video card, and do not want to replace it.

On mac.games.action is a discussion about Weekend Warrior and its
hardware requirements. The software will be bundled with the XClaim
cards and other newer accelerators, but apparently will not make use of
Apple's QuickDraw card! This seemed rather suprising, especially
considering another game, Havoc uses the card to create some impressive
effects.

The only difference between Apple's card and XClaim seemed to be
that the newer cards specificly accelerate QD3d RAVE, while Apple's card
accelerates QD3d.

I looked into Apple's developer info sight to learn the difference
between QD3d and RAVE. I found that RAVE is a rendering accellerator
based on QD3d, and can be addressed either directly by an application or
through QD3d. This is a very important point, as it possibly defines the
difference between newer cards and Apple's card.

RAVE is solely concerned with drawing the triangular faces that
compose an object, while QD3d encompasses aspects such as lighting and
camera position as well. Weekend Warrior likely uses its own engine to
keep track of things such as shapes and lighting, but uses QD3d RAVE to
output the final image.

XClaim cards, which specificly accellerate RAVE, help this part of
the process. Had Weekend Warrior been designed to make use of QD3d to
keep track of objects, it would have benefitted from Apple's hardware
accellerator, as Havoc does. At the same time, does Havoc get its full
benefits only from Apple's board (I have seen one post that might
indicate this), or can it give the same performance with RAVE hardware?

So it seems that QD3d hardware and RAVE hardware help at two
distinct levels...

QD3d helps model handling and manipulation, making it useful for
modelling and animation software.

RAVE helps final rendering, making it useful for drawing 3d based images
to screen, particularly for games.


Is this a correct analysis of how QuickDraw 3d and RAVE interact?


Does Apple's card not support RAVE at all? If not, will Apple be
working on a RAVE and/or QD3d accellerator card? And will it function as
the current card does (as an aid to other video cards)? Or does RAVE
accelleration require its own frame buffer by definition?

I should point out that one of the differences pointed out by Apple
between QD3d and RAVE is that RAVE does not support the 'windowing'
options, such as multiple screens that QD3d does.


Does a game like Weekend Warrior get no benefit from Apple's card
(and most likely not even recognise the card), or are the benefits much
less significant than RAVE hardware?


Would using Apple's card and a RAVE card compound the benefits of
both when using QD3d software, or would the output and input
requirements of the two be incompatible?


Here's hoping that someone out there might know, or have the means
to find out these answers.

Jason Davis

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Dec 21, 1996, 3:00:00 AM12/21/96
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In article <QmiqJ5q00...@andrew.cmu.edu> David Gabriel White <dw...@andrew.cmu.edu> writes:
> I decided to poke around a little and see what I could find out
>about QuickDraw 3d, RAVE, and hardware accellerators. I'm posting this
>in hopes that someone can tell me if I'm understanding this correctly,
>or possibly elaborate on the subject.
>
> [long post clipped]

Okay, here's the deal. Everybody save this message somewhere for the
next time this question is asked..

RAVE is the low-level part of QuickDraw 3D. You tell RAVE "draw this
triangle" and it does it. QD3D as a whole also includes software that
lets you specify whole objects (and other stuff). Then you tell QD3D
(the high level) "draw this object," and it basically makes a bunch of
calls into RAVE (the low level) for you, to get the appropriate triangles
on the screen. It does more than that, but for now that's enough to know.

This issue is confused a little bit because a year ago (when QD3D was
released), Apple hadn't thought to name the low-level part "RAVE". The
whole thing was just QD3D.

Now, Havoc was released with support for just the low-level calls. It
has a bunch of polygons and it uses RAVE to draw them if there's an
accelerator present. But the word "RAVE" didn't exist then, so it was
just called general QD3D acceleration. Havoc runs just fine without
an accelerator because it can call its own software polygon renderer
when QD3D isn't around.

Enter Weekend Warrior. My understanding from the authors, Pangea Software
(Bungie is the publisher, Pangea is the developer), is that WW actually
uses the high-level portion of QD3D. Therefore it is totally dependent
on the presence of QD3D, and, since it has no polygon renderer of its
own, also "requires" an accelerator. (If there's no accelerator present,
QD3D will use its own software renderer, which is pretty slow. Thus
WW requires a really really fast machine if there's no accelerator).

As for the 3D accelerators themselves, they all accelerate RAVE, that is,
the actually polygon rendering. Since QD3D as a whole involves both high-
level software stuff (for "objects") and low-level RAVE rendering, these
accelerators also accelerate a big chunk of QD3D.

Apple's original accelerator is a special case. Unlike other cards, it
only has space for 12 textures of exactly 128x128 pixels (24 bit mipmapped).
Since that was the only card that was going to be available at the time,
Havoc was specifically written to get around this restriction (and it
in fact uses many more than 12 textures at a time). The Apple board is
very high quality and very fast, but because of this restriction and a
few others, probably no other high-end 3D games will really be able to
support it.

Before people ask, our next game (Dark Vengeance) will support RAVE,
same as Havoc.

I think that about covers it.. If I left anything out or was unclear,
let me know and I'll try to clarify.

Jason Davis
Reality Bytes, Inc. (www.realbytes.com)
jda...@mail.realbytes.com
jas...@netcom.com

John W. Blackburne

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Dec 22, 1996, 3:00:00 AM12/22/96
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In article <QmiqJ5q00...@andrew.cmu.edu>, David Gabriel White
<dw...@andrew.cmu.edu> wrote:

: Is this a correct analysis of how QuickDraw 3d and RAVE interact?

No.

: Does Apple's card not support RAVE at all?

It does support it. As RAVE is the hardware abstraction layer between QD3D
and the hardware any accelerator supporting QD3D should support RAVE, and
vice versa.

If not, will Apple be
:working on a RAVE and/or QD3d accellerator card? And will it function as
:the current card does (as an aid to other video cards)? Or does RAVE
:accelleration require its own frame buffer by definition?

Irrelevant as Apple's card supports RAVE.

: I should point out that one of the differences pointed out by Apple


:between QD3d and RAVE is that RAVE does not support the 'windowing'
:options, such as multiple screens that QD3d does.

The basic difference is that QD3D is a high level API, with a retained and
immediate mode, support for a variety of geometric objects (some complex),
a file format, picking, etc.. RAVE is a HAL which works at a much lower
level. QD3D is better suited for writing a 3D app from the ground up, while
RAVE is better suited for accelerating an existing app which already has
it's own 3D engine.

: Does a game like Weekend Warrior get no benefit from Apple's card


:(and most likely not even recognise the card), or are the benefits much
:less significant than RAVE hardware?

It should benefit from Apple's card: according to Bungie's web site it
requires '3D hardware supporting QuickDraw 3D', which includes Apple's
card.

: Would using Apple's card and a RAVE card compound the benefits of


:both when using QD3d software, or would the output and input
:requirements of the two be incompatible?

With most cards the question's irrelevant, as most cards are video cards
and only accelerate 3D rendering in the display they're driving, but
Apple's card will support rendering on any attached display. Two Apple
cards will combine to increase performance, but I don't know about Apple's
with another.

I suspect that if QD3D sees two hardware accelerators it can use with a
display it will pick one and use it, in theory the 'best' one but there's
no easy way for an app to decide which is best. Apps can let the user
choose among renderers, but the only app I've seen do this is the PINK demo
app, one of the first apps released for QD3D.

John

--
John Blackburne - programmer, writer, consultant, trainer
Perl, AS, QD3D and more at http://www.hk.super.net/~johnb

zem...@earthlink.net

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Dec 23, 1996, 3:00:00 AM12/23/96
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In article <jasondE2...@netcom.com>, jas...@netcom.com (Jason Davis) wrote:

> In article <QmiqJ5q00...@andrew.cmu.edu> David Gabriel White
<dw...@andrew.cmu.edu> writes:
> > I decided to poke around a little and see what I could find out
> >about QuickDraw 3d, RAVE, and hardware accellerators. I'm posting this
> >in hopes that someone can tell me if I'm understanding this correctly,
> >or possibly elaborate on the subject.
> >
> > [long post clipped]
>
> Okay, here's the deal. Everybody save this message somewhere for the
> next time this question is asked..
>

<< REALLY LONG POST ABOUT RAVE CLIPPED

> Before people ask, our next game (Dark Vengeance) will support RAVE,
> same as Havoc.
>
> I think that about covers it.. If I left anything out or was unclear,
> let me know and I'll try to clarify.
>
> Jason Davis
> Reality Bytes, Inc. (www.realbytes.com)
> jda...@mail.realbytes.com
> jas...@netcom.com

Hmmm...interesting. I just got an XClaim VR, which has RAVE acceleration.
Two questions: 1) Are Weekend Warrior and Havoc the only games shipping
with this kind of 3D capability? 2) Do you know if, at some point in the
future, I decided to pop in another 3D accelerator, would it work with the
VR to produce even better results? I don't think ATI's documentation
mentions anything about this.

Also, since you work at a game company, I'd like to say that while the
current crop of 3D games are all pretty impressive, I wish that there were
some games with more substance, and not so much mindless killing of aliens.
I think 3D graphics technology has the potential to provide an incredible
gaming experience. I'd like to see a game which emphasizes, for instance,
exploration of alien worlds (or space, I'd love to see a game like the old
Starglider on the Amiga). A 3D RPG game would be pretty cool, too.

--
Imagine all the people...sharing the world in peace...
-
John Lennon

Chris Schmelzer

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Dec 24, 1996, 3:00:00 AM12/24/96
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In article <jasondE2...@netcom.com>, jas...@netcom.com (Jason Davis) wrote:

> In article <QmiqJ5q00...@andrew.cmu.edu> David Gabriel White
<dw...@andrew.cmu.edu> writes:
> > I decided to poke around a little and see what I could find out
> >about QuickDraw 3d, RAVE, and hardware accellerators. I'm posting this
> >in hopes that someone can tell me if I'm understanding this correctly,
> >or possibly elaborate on the subject.
> >
> > [long post clipped]
>
> Okay, here's the deal. Everybody save this message somewhere for the
> next time this question is asked..
>

> RAVE is the low-level part of QuickDraw 3D. You tell RAVE "draw this
> triangle" and it does it. QD3D as a whole also includes software that
> lets you specify whole objects (and other stuff). Then you tell QD3D
> (the high level) "draw this object," and it basically makes a bunch of
> calls into RAVE (the low level) for you, to get the appropriate triangles
> on the screen. It does more than that, but for now that's enough to know.
>

The question becomes, since Apple's card will not be real useful for 3d
games, is someone going to come out with a QD3D accelerator that isn't
also a video card... Those of us happy with our built in video don't want
to spend extra money replacing what we already have... It would seem that
if you paid $400 for a video card+3d acceleration, that you should be able
to get a faster QD3D acclerator board for the same $400 sans video....

--

Chris Schmelzer, NREMT-P
ara...@minn.net
West St. Paul, Minnesota

Jason Davis

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Dec 24, 1996, 3:00:00 AM12/24/96
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In article <aragorn-2412...@dialup-217.minn.net> ara...@minn.net (Chris Schmelzer) writes:
>The question becomes, since Apple's card will not be real useful for 3d
>games, is someone going to come out with a QD3D accelerator that isn't
>also a video card... Those of us happy with our built in video don't want
>to spend extra money replacing what we already have... It would seem that
>if you paid $400 for a video card+3d acceleration, that you should be able
>to get a faster QD3D acclerator board for the same $400 sans video....

On the PC side, both the 3DFX and the NEC/PowerVR accelerators (two of the
better ones) do not have a built-in video card. So it's reasonable to guess
that when they make it to the Mac side of the world, the same may be true.

There may be other cheap-end solutions as well (no video card features to
keep the price as low as possible).

Jason Davis
jas...@netcom.com

Leslie Shafer

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Dec 26, 1996, 3:00:00 AM12/26/96
to

Also, if you follow MacWeek, another company reported that they are
producing a 3D and video acceleration board for about $200. Try reading
these articles for more info:

http://www.zdnet.com/macweek/mw_1038/news_accelerators.html
http://www.macweek.com/mw_1038/news_ims3d.html
http://www.macweek.com/mw_1030/news_ati.html
http://www.macweek.com/mw_1042/ga_ati.html
http://www.macweek.com/mw_1013/rev_pci_cards.html

In article <jasondE2...@netcom.com>, jas...@netcom.com (Jason Davis) wrote:

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