setFeatureType is an SQF scripting command which can be used to ensure that objects will be rendered even if they are very distant. Ordinarily, even in singleplayer, most objects appear to not render beyond ~1-2 km, and this is regardless of whether or not setViewDistance or setObjectViewDistance have been increased.
setFeatureType takes a single parameter to determine how the object should render. Given a 0, the object will render like any other object. Given a 1, the object will always render if it is within the object view distance. Given a 2, the object will always render if it is within the terrain view distance.
Note that by default, flying helicopters and jets are treated as setFeatureType 2.
Note that the function returns a boolean value which determines whether or not it worked. It will work as long as you aren't trying to have more than 200 dynamically simulated objects or more than 500 static objects set to long-distance rendering. For example usage:
_functionResult = this setFeatureType 2;
This segment can be applied to the init field of an object or vehicle to ensure that it will always render regardless of distance, as long as the terrain around it would also render.