A computer-implemented method for determining an attenuation of a wind caused by a simulated obstacle (42, 44) and experienced by a simulated vehicle in a simulation, comprising: receiving a wind direction and an initial speed for a simulated wind; generating a line of sight vector having a source position (50, 52...62), a given direction and a given length, the source position (50, 52...62) being located on the simulated vehicle, the given direction being one of opposite to the wind direction and identical to the wind direction and the given length defining the maximum distance for an obstacle to create wind attenuation for the simulated vehicle; determining a distance between the simulated obstacle (42, 44) and the source position (50; 52, 62) based on topography information contained in a database; if the distance between the simulated obstacle (42, 44) and the source position (50, 52... 62) along the direction of the line of sight vector is less than or equal to the length of the line of sight vector, determining a wind attenuation gain using the distance between the simulated obstacle (42, 44) and the source position (50, 52... 62), wherein if more than one simulated obstacle (42, 44) is identified as having a position within the range defined by the length of the line of sight vector, only the simulated obstacle (42, 44) closest to the source position (50, 52... 62) is considered; if the distance between the simulated obstacle (42, 44) and the source position (50, 52... 62) along the direction of the line of sight vector is greater than the length of the line of sight vector, no wind attenuation gain is calculated; determining an actual speed for the simulated wind using the initial speed of the simulated wind and the gain for the wind attenuation; and outputting the actual speed of the simulated wind and using the actual speed of the simulated wind for controlling the simulated vehicle in the simulation. receiving a wind direction and an initial speed for a simulated wind; generating a line of sight vector having a source position (50, 52...62), a given direction and a given length, the source position (50, 52...62) being located on the simulated vehicle, the given direction being one of opposite to the wind direction and identical to the wind direction and the given length defining the maximum distance for an obstacle to create wind attenuation for the simulated vehicle; determining a distance between the simulated obstacle (42, 44) and the source position (50; 52, 62) based on topography information contained in a database; if the distance between the simulated obstacle (42, 44) and the source position (50, 52... 62) along the direction of the line of sight vector is less than or equal to the length of the line of sight vector, determining a wind attenuation gain using the distance between the simulated obstacle (42, 44) and the source position (50, 52... 62), wherein if more than one simulated obstacle (42, 44) is identified as having a position within the range defined by the length of the line of sight vector, only the simulated obstacle (42, 44) closest to the source position (50, 52... 62) is considered; if the distance between the simulated obstacle (42, 44) and the source position (50, 52... 62) along the direction of the line of sight vector is greater than the length of the line of sight vector, no wind attenuation gain is calculated; determining an actual speed for the simulated wind using the initial speed of the simulated wind and the gain for the wind attenuation; and outputting the actual speed of the simulated wind and using the actual speed of the simulated wind for controlling the simulated vehicle in the simulation.