While artpassing my map (koth_drudic) I've decided to not have all my buildings be all the same height and not have rooves. Before I had them set up so that there was a skybox brush directly above the building, covering the entire area of the building. If I had of kept them like that then I wouldnt be able to do rooves at all since the skybox would cause it to not render. So now I have it set up differently (not having skyboxes above all the buildings) but if I did that for all the buildings then the whole map would load at once. So between areas I have kept the skybox brushes. Now my problem is that you can see the map behind the skyboxes being not loaded. In hammer: In game: So is there a texture / method I could apply to either have the non-loaded bit loaded (areaportals I suppose) or have it completely invisible or have roofs using my old method (3d skybox I guess)? Also which of those methods are most effective at culling long compile times / high fps.