Assets + Accessories Ground Planes

Added six geometric plan assets:
- stadium with black background, two heights
- dark city skyline
- circular podium
- top of the world view, both black and snow material

New geometric planes with terrain features have been added. In general, the elevation of these additional terrain assets has been reduced. The new files include:
- dark green hills
- coffee brown hills
- clay hills
- dark gray hills
- sand dune hills

In testing, these new materials seem to work best using directional lighting and the forcepixel setting.

Sample images with the new terrain assets are included below.