first let me describe the map situation, simplified. One room building, outside and inside. I was told it would increase R_speeds to make thinner "ground" brushes, and place a null texture brush underneath them, since they would never be seen by players. Is this neccesary, or would the ground, connecting all the way to the edges of the map and not leaving any gaps be enough for the game engine to know it doesnt need to be rendered? (there is hollow space under my building, from a "pit" dug out, so its not a level surface) If need be Ill give a screen shot