Tech Retrospective: Burnout Paradise

"Let's just say you have to be very sensible! Very pragmatic. It isn't magic, although perhaps we'd like to say it is."

I'm sitting in the Criterion AV room with Richard Parr, technical director of Criterion Games and senior engineer Alex Fry. We're talking about the evolution of the Burnout technology over the years and at this point, Criterion's methodology in its Face-Off defying cross-platform development. Eighteen months on from the initial release of Burnout Paradise, it is still the most technically advanced multi-format racing game on console, offering a gameplay experience that is to all intents and purposes identical on both major consoles, and now PC.

This week, Burnout Paradise evolved yet again with the release of the Big Surf Island downloadable update: a brand new extension of the Paradise City open world, that you'll see showcased and explored in a brace of exclusive videos put together by Digital Foundry to complement this feature.

But to re-focus on the concept of the cross-platform "pragmatism", there is no lead platform in Criterion, no separate teams dedicated to different consoles. There is a gameplay experience that is the singular focus and the commitment from every member of the Burnout team is that this will be identical regardless of the machine you play it on. And here's where things get seriously impressive, bearing in mind the performance levels we see in the final game: the vast majority of the code is exactly the same on PS3, Xbox 360 and indeed PC.

"Very early on we made a lot of very right decisions in terms of the architecture and the software and the way we were going to approach things, which has worked extremely well for us. Our aim was to produce an architecture that would work well on PS3, 360 and PC," Parr explains.

Criterion's method of exacting the most performance from the new architecture isn't so much about threading as such, it's all about parallelisation. Rather than lump different game aspects onto different threads (where massive latencies can build as each processor waits for the other to finish its work), game code is highly optimised to make use of what processors are available at any given moment on whatever target hardware, and by choosing the all-important balance points, the experience is like-for-like on all platforms. High-level management code that is unique to each platform then processes the game code according to the hardware that is available.

"The management code, the really high-level code that manages how you parallelise what and where, that obviously can't be the same on both as you have different number of processors, different architectures," says Fry. "But the point is that with the stuff the coders write, there is very little bespoke code, it's shared across all platforms, all processors. Obviously there's a little bit that is bespoke, like online. But the key is not to 'go off on one' and do something suited to one particular platform that the others won't do very well."

With the advent of Xbox 360 and PlayStation 3, Criterion was given the opportunity to completely bin its existing tech and produce brand new code for the next generation. However, before the Paradise project began, the team had a chance to sample the capabilities of the new consoles with the Xbox 360 port of Burnout Revenge.

"We put a lot of effort into Revenge to make sure it played well," offers Alex Fry. "Visually it was interesting to see what we could do in high def; what the costs were, what we could do. Architecturally we didn't really change much with Revenge on 360. We did learn a little bit - you can't not."

"We learned a reasonable amount about what we couldn't do with the existing tech," adds Parr. "It was definitely valuable in that it convinced us that we had to make significant improvements, and that led to us starting with an essentially blank piece of paper when it came to Paradise."

The new hardware opened up huge opportunities for the Burnout team to make the gameplay experience that much more involving and exciting partly through the raw computational power available.

"With high-definition graphics, you need high-definition physics, otherwise you're going to see a lot of glitches. You just expect more," says Fry. "So we did spend a lot of time on that. High-def physics in an open world with a lot of vertical gameplay. That took a lot of time."

"The basic driving experience is more realistic. We can just do more maths, so we can think about spending more time on things like the friction coefficients of tyres, that sort of thing," Parr adds. "The cars do drive in a more physical way than they do in previous Burnouts... it's always been about what we wish driving was, rather than what it actually is. We've put a lot of effort in the drift... physically it's entirely wrong but actually, if you keep the accelerator floored it'll pull you into the bend. We spent a lot of time introducing 'magic' into the physics."

"And making sure that it doesn't break the real physics, the collisions that have to go on in the background, to stop you going through things," Fry continues. "That is exponentially more difficult in an open world."

The inclusion of that open world was the most fundamental shift we've seen in a Burnout game to date. It was a move that upset many before the game was released, but 18 months on, it is such an integral part of the gameplay that it's difficult to imagine Burnout without it, especially with regards the still-unique Freeburn online concept. Key challenges here included the streaming technology (both PS3 and 360 funnel in data from the optical drive directly) and then rendering that data at 60FPS.

"There were a number of challenges - the key thing is just to take them all on, take a look at your game design and don't try anything that's going to be insurmountable," says Fry. "You have to run some numbers, work out whether it makes sense or not. Does it roughly add up or not? Streaming... that's independent of the rendering, you render what you stream. As long as you can stream it into memory and render it on time then you're OK. So we split streaming into one focus group, and rendering into another and approached it that way. I think streaming was one of the biggest hurdles."

Bearing in mind the differences in performance for each of the optical drives in the 360 and PS3, you might think that different streaming tech would be required for each platform, but Criterion's solution effectively sums up their entire approach to cross-format development as a whole.

"Just like the consoles themselves, they've all got their ups and downsides," explains Fry. "You need to take a holistic view of all of them, and everything there, you can just pick balance points that just work on both."