Environment Improvement

Please improve the visual environment.
- Shadows are too dark. Please add something like skylight or eye adaptation. Caves are ok, they should be dark, but terrain shadows and shadows in forests are way too dark right now.
- Improve general time of day settings (colors, fog and so on)
- Fix issues with terrain rock walls in some areas (you see what I mean when you do the mission "deep vein: extraction" entering the snow biome from the south and stick to the left terrain wall. There are some walls that are partly invisible and getting visible when you go right next to them.
- Improve the sun. this small thing looks terrible. Maybe add a decent lens flare.
- Improve underwater effects. take a look at Crysis underwater for example.
- Lots of river junctions are looking terrible underwater because you can see the layers floating into each other,... please fix that,