Break

 I didn't get time for any Blender, yesterday. A rare thing! I'd only had three hours of sleep and my head never quite made it to planet Earth.

I did some drawing for a t-shirt. It's based on a sculpture in the grounds of my son's school. 

It really is time to get this giant terrain scene done. I'm looking at how I need to change my approach to accommodate its massive scale.

1) Smoke and mirrors
I need to stop trying to brute-force full scenes with high-poly scatters. There really shouldn't be any scatters at this altitude.

2) Consider using render layers

Instead of doing the whole scene in a single pass, break it down. It takes a lot more planning, but it can be the only practical way of rendering especially complex scenes.

3) Look at what the top artists do
There are plenty of great Youtube videos that cover terrain scenes. There are a couple of courses too. I still need to finish one of them. (Ultimate 3D Environment Animation Course - Blender)