Frank O'Connor on how Halo 4 gets the most out of the 7-year-old Xbox 360

343 Industries is set to keep faith with the existing Halo engine for future Halo games.

Halo 4, due out on Xbox 360 in November, is built using a heavily modified version of the engine established by Bungie. Parts of it are completely new, but the core that served Halo: Reach and previous Halo games so well remains. But with Halo 4 being the first in a planned trilogy of new Halo games, and with the next Xbox looming ever larger on the horizon, 343 would be forgiven for building a new engine for Halo 5 and beyond.

According to Halo boss Frank O'Connor, that's not the case. He told Eurogamer this afternoon that 343 can use the core of the existing Halo engine even on new hardware.

"In a world where we're working on next generation platforms, there's things we'll have to do just for architecture to make it work. But ultimately you just keep evolving the things that make it work. In the future we'll probably have to radically overhaul systems yet again. But as a building block or a foundation for future Halo products, especially FPS stuff - obviously Halo Wars doesn't have a heck of a lot in common with Halo 4 - there are absolutely components and elements you have to keep because they're essential and core to the heartbeat of the game.

"Sometimes you're going to have to completely throw out whole chunks of the engine. But yeah, there are always pieces you can keep. Some of that is just calculations and numbers that make his jump height feel right for example. That stuff you have to retain."

Back in the present, O'Connor delved deep on the Halo engine used for Halo 4, explaining that 343 stuck with it to make sure the game felt like Halo.

"If you got an engineer from back in the day, from 2001 or even 1999, they'd recognise elements of the code in there," he said. "Part of that is retaining the spirit and feel and core principles of the game. They're in there. It's lightning in a bottle and you have to keep it in that bottle.

"But we've also torn down the engine and rebuilt a lot of it, and certainly you've seen that in the image quality and the graphic rendering techniques we're using. But we've changed things like audio. We've made some improvements to the network code. And some things have been radically redone from scratch, and some things have been tuned or tweaked. But it's absolutely an evolution of the engine."

O'Connor said discussions about game engines can get "confusing" because they're often described as new but are, essentially, evolutions of old technology.

"Halo's engine is really fascinating because it does so many different things. It's got this really compelling physics aspect. It's got the sandbox stuff. It's got the open world. It's got the way it streams in environments. It's a big complicated convoluted engine.

"One of the biggest improvements we made to it was making it more malleable and more iterative for artists. That's alone would have produced better results even if we hadn't made changes to the rest of the technology."

Unlike previous Halo games, Halo 4 runs natively in 720p resolution and comes on two discs. It also looks lovely - not quite as good as some of the screenshots released by Microsoft suggest it may, but at least as good as the best-looking games on the console.

O'Connor put this down to three things: the time 343 had to experiment, the technology and the good work done by the team's artists.

"The one luxury we've had is time," he said. "A significant amount of time has passed between Halo 3 and this, even Halo: Reach and this game. We also had a luxury that some teams don't get, which is we had some time to prototype, pull the engine apart and look at what made it tick and see where we could make improvements, because we weren't on this grind to build the very next sequel.

"The second thing is technology. We have some great engineers working on these problems and they've written some amazing code to enable these things.

"And thirdly - we have more pixels on the screen; it's native 720p - but one of the reasons it looks good is we've given our artists better tools to iterate with. You get some of the strongest positive feedback when artists are able to iterate really quickly instead of being constrained by the technology and the tools.

"So it's a combination of technology and art and time. That's all it is."

There's still life in the old girl yet. This is already one of the longest generations we've had. And just in terms of being an element of your home entertainment, the Xbox 360 and the PlayStation 3 are essential. You have to keep it under your TV. I cannot get rid of my Xbox - Halo boss Frank O'Connor

O'Connor said Halo 4 is a testament to what the Xbox 360 is capable of nearly seven years into its life, and he doesn't see the console losing its usefulness even when the inevitable next Xbox launches.

"The console is seven years old but we keep finding new tricks and new abilities to wring performance out of it," he said.

"There's still life in the old girl yet. This is already one of the longest generations we've had. And just in terms of being an element of your home entertainment, the Xbox 360 and the PlayStation 3 are essential. You have to keep it under your TV. I cannot get rid of my Xbox. The machine has so much utility it ends up being a hub for all these experiences and can still put out triple-A quality entertainment experiences as games. I love that. I get so much value out of that box in my house that I literally can't understand any reason why I would want to take it out from under my TV even if it gets replaced by better hardware in the future. It will still be useful somewhere in the house.

"The example I use is, if the Wii had had DVD playback and a HDMI out I wouldn't have put it in the closet already. Once I was done playing the games I wanted to play on that machine it didn't have any further utility for me. So it was easy to put it away. But with the 360 and the PS3, they just do so many different things they have this tremendous utility. And that in itself keeps me engaged in games on them because I'm using it a lot. I go into my dashboard and sometimes I get distracted by a game instead of a movie. I just have so many different entertainment experiences to pick from when I get into the dashboard."