Calling all optimisation experts... I've got to the stage in my map where I should probably start adding hints and stuff to keep compile times down and fps up. I've looked at some tutorials and I thought I understood the basics of optimization, but now that it comes down to it I'm not sure what the best approach would be in this section of my map: The pipe cylinder connects the top and bottom room and is a func_detail (may become a prop later) but of course I don't want to render the middle room when you are in the top or bottom rooms etc... So this is where I'm confused. Even if I add some square hint brushes around the cylinder, because it's a func_detail it's not going to block visibility and everything is going to get rendered anyway. All I can think of is walling off the cylinder with 4 rectangular brushes, but that will ruin the look of the layout for me and I'd rather avoid that if possible. Is there anyway to optimise this layout, or will I have to make the cylinder a world brush and just put up with huge vvis compile times to make it playable? Thanks for any help!