by Keith Charley of Creative, the idea behind Eagle is a tool that
loads up the raw map file that designers use to create their game
levels, and creating a low polygon version of it that contains all
the information necessary for setting property sets, as well as
data necessary for obstruction and occlusion, which we will talk
about a bit later.
As a tool, its
a great idea, but it does have some drawbacks too. Firstly, it's
an extra step in the designer's development cycle. After building
your level, you have to set up all the sound info the game requires
too. Any change to a level requires the same change to the sound
map as well. Secondly, the map that it generates is extra data that
has to be loaded per level. It increases memory consumption, and
adds to the load time. Both bad things, especially if youre
looking at complex levels to begin with. However, the one thing
that it does offer you is that you end up with geometry that is
purposely designed for the job of adding cool sound effects to your
game. It's fast to access, which is something that comes into play
in the obstruction/occlusion areas.
Something else that should
to be discussed is the move by Microsoft to include EAX support
inside of DirectSound. In their quest to support hardware sound
cards, Microsoft decided that EAX was the way to go. This could
be seen as both a drawback and a plus. A plus in that many people
can now use the EAX protocols, which means you don't have
to have a SB Live! to use EAX, just a card that can support its
property sets. This is a double-edged sword though, since EAX could
now be applied to a card that really isn't made for EAX support,
resulting in a sound system that doesn't do either the card or EAX
justice. It can also be seen as a drawback in that Microsoft have
a way of usurping control of systems like EAX to their own ends.
Aureal offers a comprehensive
solution. The A3D system has its own way of doing things that covers
almost all the bases, and what it doesn't, it will soon. Currently
its the major competitor for Creative Labs in the sound card
market. They offer a similar solution to EAX called, not surprisingly,
A3D. Their homegrown chip is the Vortex chip set, although A3D will
run on other systems. Interestingly, Creative even had a small A3D
emulation driver they shipped with the SB Live!. A3D is not property
set based, although coming in A3D 3.0, they will have A3D sets,
which just happen to map to EAX property sets, meaning that effectively
you can run A3D on a property set supporting card. Draw your own
conclusions about what this will mean. Also supported in A3D 3.0
is .mp3 decompression. It's software based, so it's not free, but
it would certainly be worth investigating for those music channels.
Something worth mentioning is that Quake III will support A3D 3.0.
This is bound to boost the popularity of this sound system.
As it stands right now,
there are tools being created to allow easier access to A3D functions
- but it's hard to comment on them without seeing them.