This is a step by step tutorial showing you how to do a basic lightmap for Battlefield 2.
It will show you which buttons to press in Battefield 2 editor (BF2Editor) and where to move the lightmap files to get it working in your level.
There is also a quick tutorial about shadow maps which are not lightmaps, but do affect shading.
The light mapping tutorial is in PDF format and is available for download in the Battlefield 2 - files section. See the link below:
Beginners Guide to Lightmapping - v2
