FlatOut Ultimate Carnage

Feature: Just how does Bugbear create such wonderful car destruction?

FlatOut Ultimate Carnage: Technical feature


1. Introduction
Bugbear Entertainment has always focused on developing advanced driving games that push the technology envelope and provide a highly compelling game play experience. One of the absolute core experiences of the FlatOut series has always been vehicular destruction: using your car to deal out damage to your rivals and to the environment.

The end result of vehicular destruction is of course always car damage (be it to your car or to a rivals car). Creating a truly compelling car damage modeling system in FlatOut has been an absolute key feature and we've dedicated a number of people throughout the projects to ensure that FlatOut is always pushing the technology envelope.

For FlatOut Ultimate Carnage our goal was to simply deliver the best car damage we've ever done. Now, let's see how that works out in practice.

12 cars shooting off from the starting grid. Closest to the camera we have Speedevil, the star of this crash test.

2. General about FlatOut's cars
FlatOut Ultimate Carnage boasts 12 cars racing side by side. Each of these cars is lovingly modeled with approximately 25 000 polygons (roughly 3 times the average of 7500 polys in FlatOut 2) and polished with a number of highly detailed shaders (e.g. metal shaders, paint flake shaders). Things of beauty indeed - and ready to be demolished!

The car used in as an example in this technical featurette is called Speedevil. This particular consists of over 30 000 polygons and another 16 000 polygons for its crash model.

The car damage modeling systems builds on four main components:

  • Deformable mesh
  • Detachable parts
  • Damage textures
  • Particle system
Example of deformable mesh: Speedevil impacts with a concrete divider smack in the middle. See how the center section of car has deformed including the crumbling hood.

3. Deformable mesh
In essence, each car is modeled twice. First in a pristine condition and second time as completely, and utterly wrecked condition. These two different car meshes create the ends of the spectrum for the car deformation sub-system. When the car is hit, the vector of that impact (i.e. the impact point, the direction of the force and amount of force) is used to deform that particular point of the vehicle. Thus every time the car is hit, the car deforms where it was hit and according to the force of that hit.

The great thing about a deformable mesh is that allows for almost infinite number of different types of deformations to occur and those deformations match the impact very closely. . Effectively this means that when the player hits a telephone pole head on, that pole creates a wedge in the front of your car, but if you hit a large building head on the whole forward section of your car deforms simultaneously.

See how the engine is just catching fire (is not yet completely engulfed by flames), sparks are flying as the car hits the object under water and how the car splashes the water in its wake.

4. Detachable parts
Each car in FlatOut is composed of approximately 40 different detachable parts. Typically these include the hood, doors, windows, side mirrors, spoilers, mufflers, headlights and even wheels. These parts can be ripped off by the force of an impact or they can be damaged so that they start to swing on its hinges and eventually tear off with subsequent damage.

For example, if a door of a car is hit and the set damage level is reached by either one or several impacts, that door's lock will open and the door will start swing on its hinges depending on the car's movements. If the driver is powersliding around a corner, you'll often see damaged doors swinging with the car's powerful movements. Once that door reaches critical damage it will tear off completely leaving the cockpit and the driver exposed.

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