Shack: What, if anything, has gone into adapting the DOOM 3 engine for such huge environments? It's definitely out of character with most of the games based on the technology.

Paul Wedgwood: When we started working on the initial design with Kevin Cloud (Co-Owner of id Software), we knew that to evolve Wolfenstein: Enemy Territory's game-play to the level we all wanted, we needed an engine that would support terrain rendering, multiplayer gaming and vehicle physics. It's a great testament to id Software's technology that Doom 3, which appears to be a single-player, indoor, first person shooter engine, could prove such a great foundation for this new genre.

The big technological advances then have been in terrain rendering, physics and networking. We've evangelized the features of the MegaTexture so much that people must think that ETQW's networking and physics are its poor inbred cousins, but in fact these are both areas that have witnessed similar advances.

For the networking, we devised a system with id Software called 'Area of Relevance', which works somewhat like 'Level of Detail' for graphics - it only sends the data you really need to know about. For example, up-close you'll see the entire inventory of a team-mate, but at a mile away you don't need to know which way his head is facing or how many grenades he has, so we don't transmit this information to you. For the game's physics, we've extended the implementation of 'rigid bodies' so that suspension, propulsion and friction are better simulated. This lets us have great off-road vehicles that can climb rocks, boats that have buoyancy and flying vehicles that react the way you'd expect to lift, drag, thrust and friction. It has a great affect on gameplay, because players controlling vehicles in ETQW find that they handle the way they'd expect - for example, as their skill improves they can start to perform trick jumps, giving them access to more routes across the battlefield.