Max View Distance
The max view distance (beyond which z-buffering will not work and objects will be visible through terrain and other
issues) is by default 256 units in the engine. When using the provided "cam_ext.cfg" it changes it to 512. However,
regardless of what user setting the max view distance is, a mission author may set a mission specific minimum view
distance required to correctly render the mission. It would be appropriate to do so for any mission that requires
more than the engine default of 256 units.
For example if you have a mission where you have a large open area where the player can be positioned such that he
could see other parts nearly 400 units away, then setting the minimum required view distance to 400 would ensure
that everything always renders correctly, even if the user happens to have a shorter max view distance set. While
it certainly doesn't have to be precise, haphazardly setting excessively large values isn't recommended as it would
unnecessarily reduce Z precision.
The setting can be found in "Rendering Parameters" under "Mission Parameters..." (edit_file_vars), and is called
"Required View Dist". The default is 0 which means the mission works fine with the engine default (256).