I wrote a small tool to edit the lighting of BSP files a bit (that is, scale color values).
Download here: http://mensa.ath.cx/~polzer/temp/bspscale.c
License: MIT "do-whatever-you-want-with-it-but-dont-blame-me-if-it-goes-wrong" license
Warning: the program writes into the given BSP file, it edits it in place. So keep a backup copy of your BSP if you want to change values... in other words, ALWAYS use it like this:
cp bleach.bsp pimp-my-bleach.bsp; ./bspscale pimp-my-bleach.bsp global-mat 1,1.2,1 0,0.2,0 1,1.2,1 global-mul 3 3 3
Windows users replace cp by xcopy /y.
Have o-fun, oh sorry, p-fun!
BTW, the program can scale lightmap and lightgrid independently, so it can be used to fix the lightgrid on maps like facing worlds nex where players are generally too dark:
cp facing-worlds-nex2.bsp facing-worlds-nex3.bsp; ./bspscale facing-worlds-nex3.bsp lg-mul 2 2 2
Small warning: it currently can only edit the lightmaps on deluxemapped maps. Non-deluxemapped maps will appear broken (there is no simple way to autodetect that). The grid, however, can be edited on all maps.
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