The main difficulty in off-road competitions is to overcome various obstacles Ė deep mud, quagmires, steep slopes, rock outcroppings and wind-fallen trees. This means that the gameplay in its core isnít about fast driving like in many other racing or rally games, but driving in extreme conditions that demands a lot from the vehicle and its crew.
The innovative system of interactive surfaces was developed specifically to re-create the unique experience of off-road competitions in a game. Off-Road Drive takes into account not only the friction level between the wheels and the ground which changes depending on a surface type, but the surface itself which is being affected by the passing vehicle. For example, dense mud will spread and the vehicle may bog down; a car will leave ruts in soft ground and may start skidding in it; grass will be torn out by tire treads, leaving slippery soil patches. All this helps to simulate specific (but very important for cross-country driving simulation) effects like skidding and sideslip.
The drive on different surfaces will be accompanied by realistic special effects: dust trails on dry ground, mud launched by the wheels of a skidding vehicle will even settle and dry out under the sun, forming a dense crust. If a vehicle crosses water after that, the dried mud will get soaked and partially fall off with visible water tracks.