s. We can use a more tricky data structure of our patches than just a simple grid - a quadtree. This will allow us to do quick and effective occlusion. Do not forget that when checking whether a quad is in or out of the frustum, that the nodes are not simply 2D squares but also have a third component - height. Cylinders can be reused, as they have already been prepared for an "up" orientated check.
Spatial sorting
Once built (tessellated), our triangle binary tree can be used for "back to front" or "front to back" sorting of the triangles, which can increase performance or help us with special effects. Before making recursive calls, we only need to check which child is closer to the camera and then use the appropriate call order.
Back to front: if you do not have
