Requisites
Even fairly optimized maps can take a long time to compile VIS, therefore it is useful to compile only CSG and RAD if you only want to make adjustments to lighting or other entities.
-onlyents
This is the faster method. If you compile your map with the -onlyents parameter in CSG, it will overwrite the entity data lump in the map without affecting the geometry, lightmaps, cliphulls or visleaves. Afterwards, you can compile with RAD normally.
Ripent
Instead of CSG, I will be using Ripent, a tool used for exporting and importing entity data. You can move and rotate entities, delete entities and even create new entities that use existing brush models. I will be using Ripent to edit the light entity before recompiling with RAD.
Export
Use the command line to run Ripent on your map with the
-export
parameter. This will create an ENT file in the directory your map is in.
Modify
Modify the entity file as you see fit.
Import
Import the new entity file with the
-import
parameter. If you have baked textures (
zhlt_embedlightmap
), it may be a good idea to use
-deleteembeddedlightmaps
too.
Compile
Compile your map with RAD.
If you reload your map in-game, you should have the new lighting.