The terrain entity uses its triangle surfaces as clipping planes. No additional clipping is required to allow characters to run on the terrain’s surface. As the initial terrain maps developed in house, we discovered that to control and guide play flow, we needed to clip many of our mountain and canyon slopes with vertical walls. Done right (as the slopes start becoming too steep to climb), players don’t notice (as much).

      Next, decide how far up in the sky you are willing to let your player’s fly. If the map is entirely open you might want to keep it that way. If you’ve placed caulk barriers as described above, then the low point on the ridgeline (or lower) will likely be your ceiling height.