How do you have a ‘short’ distance like in this video? Where you can’t see that far?
I’ve never done this, or I just can’t remember correctly on how do it.
Think you might be thinking about the post effect fog, maybe. 
Turn fog on in the lighting window (scene tab). Also might as well lower the camera far clipping plane, which will help performance as a bonus.
–Eric
I already had it enabled, but it barely even works…
Works fine here, but pay attention to what the info box says.
–Eric