TreeFX for Nordschleife - 3D Trees 1.51

- Added seasonal changes

- Added an experimental preset called Max-20000-Experimental where I will be slowly replacing the entire track with 3d trees, its currently also the only one with baked AO, for faster loading and the first part of the track where I removed the cardboard 2d background trees. Currently this preset has 20k trees, nearly all newly added are to the hill at Breidscheid, but will be slowly working on other locations as well.

A few bigger updates for 1.5:

- Removed a lot of 2d models especially near the road. So you shouldn't notice them anymore at all. I have added a few new trees to offset but the number is still 17000 due to removal of some others.

- Added 4 new tree types, so now it totals to 6, which adds a lot more variety to the track. The new models replaced the existing ones that were repeating.

- Added a skins folder, where I've color corrected a bunch of distant tree textures, as they were way too bright compared to 3d trees, so now it looks much more unified.

- Done another pass and fixed some tree positions to better reflect latest videos from the track.

- Added new ultra low preset with just 1250 trees for people with lower end PC's.

- A fix for trees overexposure in the rain and especially in the night rain. They should look much better in those conditions now.

- Lowered the tree size a small bit (10% or so), hardly noticeable but should improve overall performance.
- Some tree color corrections, and other fixes, lightning should look better.
- Removed some floating, incorrect and clipping trees (more work to be done, still some clipping on the track).
- Removed a few incorrect trees, should also improve performance a tad.

- Added Super Low Presets that now contain 5200 trees only.

- Fixed some wrong tree placements and sizes in the first sector.