A couple of things to talk about today.  First, I’ve finally put in some frustum culling functionality.  Basically, this is some maths to try to determine what objects are vaguely in front of the camera, so that we don’t spend GPU time drawing things that turn out to be behind the camera.   With four square kilometres of terrain being drawn, anything I can avoid drawing is going to help speed things up!  (Actually in the above shot, we’re sending less than two square kilometers of terrain to the GPU to be drawn;  the rest has been determined to be outside of view)

Second, as you may notice in today’s screenshot, I found a little bug in the terrain drawing which was causing the  “shag” effect to vanish from north-facing and south-facing slopes.  I also fixed a bug which was sometimes causing the “shag” to draw in a subtly incorrect shade.  Finally, its length now changes based upon the surface.  I think it looks even better now;  I’m quite happy with the effect.