This entity is available in ZHLT and forks such as VHLT but it is not available in the original Quake/Valve tools.
This entity can act as a replacement for a
lights.rad and <mapname>.rad file, in that it simply resides within the map as a point based entity. The usefulness of this is that each map can have its own unique ambient
texture lighting applied to it, and those settings will travel with the map and not affect any other maps. There is a third alternative if you want the map-specific texlight values to be its separate file, and that is to have a RAD file named
<mapname>.rad
placed alongside
<mapname>.map
.
Usage of the entity is much like that of the
multi_manager. To add an entry (take smart-edit off if you are using the Valve Hammer Editor/Worldcraft) and add key-value pairs in manually; the key should contain the name of the texture to apply lighting to, and the value a set of 4 numbers representing the red green blue luminosity(brightness) of the texture, just as you would in the
lights.rad and <mapname>.rad file.
The presence of this entity will not override the
lights.rad and <mapname>.rad file - both the values specified in this entity and the
lights.rad and <mapname>.rad file will be used by HLRAD assuming they are distinct. In the case of duplicate entries, the latest one takes priority over the first one (if you have
LIGHT1 255 0 0
which is red and
LIGHT1 0 255 0
which is green, green takes over red). Worth mentioning that
lights.rad and <mapname>.rad is read first and
info_texlights
are read last.
e.g.
LIGHT1 150 200 255 2000