Developed 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, it’s 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 you’re 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 it’s 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.