Ubisoft’s Snowdrop engine is quite impressive. You just need to load up The Division to see how good it looks and how well it scales to various hardware configurations.
The catch though? Snowdrop was built with cities in mind. Large towering skyscrapers, banks, abandoned shopping centres and apartment blocks, dilapidated parking garages.. except Pandora doesn’t have those.
To get Avatar’s world of amazing flora and fauna looking right, Snowdrop needed several tweaks. Part of this was generating enough plants to make the place look like a wilderness wonderland, then making sure that your system doesn’t come to a grinding halt trying to render all that magnificent foliage.
Add in ray tracing for bioluminescent plants and critters and suddenly I have a strong urge to go for a slow walk through a mighty forest, just enjoying the sights.
Or you could fly up into the sky, which new has volumetric clouds to make sure things don’t look terrible when you are up there.