As well as that, the guy who did the force-feedback on the steering wheels and invented some of the car physics is actually an FIA licence holder and used to drive touring cars in Hungary. He's quite experienced, so he knows what he's doing with the wheel.
Grimbley: In order to include a car, we first have to approach the manufacturers. Once we gain access to the cars, we take hundreds of photographs and get any kind of technical detail we can lay our hands on. But we also go a couple of steps further and actually question people who've driven the car to try and find out about its nuances.
It's then modelled in-game and we might have to send the manufacturers a screenshot, pull them into the studio or let them have a go on the car themselves - basically, trying to get their approval. Only when they're happy and they say 'that's a good representation of our car', do we then get approval to use it in-game.
Obviously, our damage model is probably the most extensive in any racing game, so manufacturers think, 'Oh, hold on a second, you're going to smash my brand new car up' - so we do have to work quite hard to negotiate with them. However, once they see how it works in-game, they normally go with it. The only thing we're not allowed to do is to set fire to cars. I think it's because the characters can't get out and it implies that people could be injured.
Askew: A lot of effort went into the behaviour of the damageable track objects, in order to ensure that they reacted realistically when struck and caused sensible levels of damage to the vehicles. We also wanted this to influence gameplay too.
For instance, if you're heading towards a metal-framed advertising banner which has been knocked onto the track, you may choose to plough straight through it rather than risk an accident with another vehicle by swerving. However, if you were heading towards a tyre stack in the same situation, you'd take your chances with the other vehicle!
Ridgway: If you do go off into the bushes, some of them will bend out of the way and damage the car, and some of the advertising banners and Armco won't just stop the car, they'll actually deform and crease out of the way.
In addition, if you take a corner really well, flat out and your tyres are right near the edge of the track skidding round, we made it so that you can hit all the mesh and the poles at the edge of the tracks, and they'll just ping out and the mesh deforms around the car. That way, it looks cool and doesn't punish the player.
It'll Polish Out
Askew: Our damage engine was worked on by our senior physics programmers, one of whom draws from personal motor-racing experience. Underneath the damage engine we have finite element model simulation, which drives the level of deformation that's applied to the vehicle components.
In addition, the vehicle artists have the ability to configure each car individually. This includes specifying the physical properties on a per-component basis. In the game, you'll observe exterior panels that scratch, dent and ultimately fall off, revealing structural components of the vehicle.
Ridgway: The team would separate the car into loads of different meshes so that the actual meshes could detach. If you hit a wing and the wing damages sufficiently, it actually crumples and separates off. This means the car's made up of different body parts, in the same way that the real-world version would be.
Making A Racket
Bawler: We wanted to make the audio as dynamic as possible. When the car crashes, the way the sounds are triggered and mixed together mean you never really hear exactly the same crash-sounds twice.