-dirty

[fromhell]

Ever play with that q3map2 compiling switch for lighting? I think it looks kind of neat.

Basically, it shades those corners and edges in the dark to appear even darker, giving more volume into the lighting. Unreal and Deus Ex use this alot.

[Giuseppe]

From wikibooks

-dirty

Enables ambient occlusion or "dirtmapping".
Basically, less-visible areas (such as nooks and crannies, cracks and crevices) will become darker.
This simulates a dirty, grimy effect.

and also there is

-dark

Enables darkening of lightmaps at brush/lightmap seams.
Sort of like a half-assed occlusion pass, ends up looking a bit Unreal 1-ish. Very subtle.


I used sometimes -dirty but i prefer no dirty, but sure is a personal preference

[cosmo]

Neon_Knight and I used it in almost every map although it depends on the map and its theme. oa_koth2 for example uses both, ctf_compromise only -dirt (plus -dirtdepth and -dirtmode and -dirtscale) because -dark had a negative effect on phong shaded surfaces (the sand).

[Neon_Knight]

-dark is one of the switches I always use. Almost all of my maps are set on the night. I didn't used -dirty.
Learning the goodness of func_grouping brushes helped me too to fix some stuff, like the pit glitches on am_galmevish2.