   Cloudy fog
  Hello,I need to create an effect of volumetric fog. And I want it to be "cloudy". Something like on this image: http://www.gebauz.com/uploads/images/screenshots/pentag/pentag05.pngHow could this be done?   
  Basically these are just a couple of particles filling the room.look up "soft particles" to find out how to get a smooth transition at billboard<-->geometry intersections   