Tune default shadow settings
The default shadow settings are probably not optimal for anything. Of particular note:
split point uniform logarithmic ratio
This is definitely better at 1.0-ish for high viewing distances. I remember at one point, it was best at 0.5-ish with the defautl viewing distance, but have conflicting reports from people doing more recent testing.
split point bias
The PSSM paper recommended having this as a tunable parameter, but I've jsut left it at zero and not meddled at all.
compute tight scene bounds
This usually has a performance hit as it does a bunch more CPU-side work, but often it's less than expected as it then means fewer objects actually end up in the shadow maps and then there's less work because of that. It definitely increases shadow quality. Tis is a case of debating whether we want the default settings to be good or fast. This setting may be made redundant (or less useful, or maybe have a level between off and on) if bzzt's water plane bounds adjustment gets merged.
minimum lispsm near far ratio
This value was chosen back when shadows were total garbage, so it's almost certainly wrong. A better value may help or it might turn out than now other things have been sorted out, it doesn't matter any more.
use front face culling
When the real and interpolated face normals are very different, meshes can have light bleed through them with this enabled. If Bethesda were competant at making meshes, this would never be an issue, but they're not, so it is. That means that things can look bad with this enabled, but if mesh replacers are used for the dodgy meshes, it should be safe to have enabled.
When testing, a range of lighting situations will need to be compared - if a certain value makes things look a little better at midday, but terrible in the evening when the sun is low, we obviously don't want to use it.