to address the lag problem of the mist, fog and flying particles. I strongly recommend at least using the meshes, they are very helpful and i don't know of anyone that did these specific mesh tweaks before. You don't need this if you are not having any lag. Clear Weather : An optional 'Clear Weather file, to prevent the lag caused by some types of weathers.Meshes (file 2) : these meshes tweaks the flying particles, fog and mist, for more FPS (see details bellow).