Arena

So the game takes place in the atmosphere above Venus.

Ground radius: 6,051.8 km
Scale height: 15.9 km
Surface gravity: 0.91 G
Surface pressure: 92 bar
Surface visibility: ~3 km
Kármán line: ~165 km

ExponentialHeightFog - basically need one setting for below the upper cloud layer (BCL) and one for above the upper cloud layer (ACL) ... or maybe we need to modify it as we change altitude through C++ ... I am not entirely clear yet except that the exponential height fog is much more realistic than what we used to do ... we should not be able to see the ground above ~3 km? Should not be able to see the lower cloud layer until what altitude?

Tune the 50 km layer so large structures are readable at 5–10 km, with the far horizon fading out by 15–25 km.

Modern reviews place the lower cloud layer at about 47.5–50.5 km, and probe data show a sharp increase in extinction just below 50 km, with the lower cloud layer having visible optical depth around 6–12 in some measurements.