Visual Upgrades
If you don't already have a Systemcfgoverride.cfg file inside your Far Cry folder, then make one. Standard ANSI text file. Use some caution with visual settings. Some combinations can break the game or cause visual glitches.

Bush sprites
This will stop bushes [and maybe trees?] from turning into sprites at absurdly close ranges.
• Paste e_vegetation_sprites_distance_ratio = "999" into your Systemcfgoverride.cfg
Now start the game, and enjoy. It does not need to be at 999, smaller values will likely be enough
Common Knowledge
Corpse de-spawn time
This will stop enemies from despawning quickly, improving realism.
• Paste p_deathtime = "999" into your Systemcfgoverride.cfg
Smaller number will work too
Common Knowledge
Distant objects
Should improve distant object looks depending on value and give them more realistic shape.
• Paste e_obj_min_view_dist = "80" into your Systemcfgoverride.cfg
Smaller number will work too
Common Knowledge
Item fading
Makes all objects(that fade, stuff like towers,boxes,smaller object) visible no matter the distance, it is disabled by default because of optimization. Now distant objects won't fade and become transparent and eventually disappear when you are far away. (has limits ofcourse )
• Paste e_objects_fade_on_distance = "1" into your Systemcfgoverride.cfg
Common Knowledge
Terrain quality
Improves the distant terrain quality , it's set to 1 by default because of optimization, setting it to 0 will improve distant terrain looks.
• Paste e_terrain_lod_ratio = "0" into your Systemcfgoverride.cfg
Common Knowledge
Sun reflection on water
Enables effect of sun reflecting on water.
• Paste e_water_ocean_sun_reflection = "1" into your Systemcfgoverride.cfg
Common Knowledge
Water refraction
Enables refraction effect on water, disabled by default.
• Paste e_waterRefractions = "1" into your Systemcfgoverride.cfg
Common Knowledge
HDR rendering
The value shown above can be anything between 1 and 11 (7 being the sweet spot, but it's up to the user prefernce mostly), note that you need to have your game patched to 1.3 at least and disable AA(Anti-Aliasing) in order for HDR to work properly. Using both at the same time can cause visual bugs and other issues, but you can try for yourself.
•Paste r_hdrrendering = "7" into your Systemcfgoverride.cfg
Common Knowledge