Unity Terrain and Environmental Tutorials

Unity 3D Scene And Terrain Optimization with Gaia – This article covers a wide range of suggestions to improve your performance and frame rates and is worth a read.

Optimizing SpeedTree for GPU Instancing – Unity 5.5+ – This article shows how to set your scene up and optimize your SpeedTrees. This can make a massive difference. Gaia 1.6+ now does this by default, but you will still need to make the SpeedTree changes for any other trees you introduce into your scenes.

Unity 3D Game Optimization And Lighting Articles – This article contains a bunch of links to other articles on optimization and lighting.

There are a lot of tutorials on this site – for product specific tutorials check out Gaia, GeNa, CTS, Pegasus.