Close-up and distant terrain lighting

Normal-mapped detail textures are effective at conveying close-up detail, but don't add too much in the distance. In Overgrowth, the players will spend most of their time looking at the terrain. We want to make it look as interesting as possible, even far away! Here's how the desert terrain looks with just detail textures:

We still have the baked normal map from the high-detail terrain heightmap (before our OffTheGrid simplification), so we might as well apply that in the distance! If we combine the heightmap normal map with the detail normal maps, the lighting should look nice both close-up and far away. This picture shows the detail normal map on the left, the heightmap normal map in the middle, and the combination on the right.

Here's a comparison of the complete rendering using detail mapping on the left, and the hybrid approach on the right. You can see that with the hybrid approach, the ripples on the sand dunes are a lot more defined.

Here's another angle on the desert terrain, showing both detail normal mapping and heightmap normal mapping.

There are a few more ways we could improve the terrain lighting, but I think at this point our base terrain rendering is good enough! With high-quality terrain lighting, we should be able to effectively render a wider variety of terrains than just the rolling hills seen in most games. Do you have any ideas for interesting terrain types that we could use that are not often seen in games?