But that is the fun part. If wind can be controlled, one can just make it blow from behind and keep the sail perpendicular to the wind, to move in any required

But that is the fun part. If wind can be controlled, one can just make it blow from behind and keep the sail perpendicular to the wind, to move in any required direction. Anyway, I have turned off randomizing wind directions at load and have added a check box to enable/disable it.