Yea it could be that, but then you wonder why would you even have such heavy fog that it adversely affects one of the main game design choices. It's really doubtful you would see fog like that much of anywhere, and fog of that level that obscures everything in the distance into one flat colour could probably be cut out of the game entirely and be better for it. I'm certain that sort of fog is used purely for performance target reasons, which is probably dependent on each area.@OliverDK Yeah I think that chimney smoke is gone, as it's purely volumetric. I'm thinking it would be a crazy performance hog in Novigrad.
@Salulu The screenshot Sneky has posted in page 38 is pressive impressive in regards to the draw distance though. It might be just the actualy fog here. I can't know for sure of course.
Could be that some areas aren't as intensive, and hence fog is toned back to show more of the landscape, and visa versa for performance intensive areas.
And it's funny you bring up the picture on page 38 and chimney smoke being gone in the same post, since you can see a house with chimney smoke in that exact picture!