In each step of the simulation, structures are thoroughly checked and errors are reported. Death - creature dies when its energy reaches 0. These parameters describe how the genotypes' fitness is calculated. Velocity and Distance are calculated from creature's center of gravity position measured during its lifetime. Velocity precision parameter changes 'sampling period'.
High values let only smooth, straight moves be counted.
It's useful when the criterion is speed or distance. Two methods are possible. Thus, 'fitness' becomes a 'fitness ratio'. The motivation is to include creation costs into the final fitness. It can lead to more fair competition, although the real advantages and disadvantages of this approach haven't yet been tested.