Battlefield 2: Unlimited Action is a Battlefield 2 modification which improves upon the base game by fixing many inconsistencies and glitches that were disregarded by EA/DICE, as well as adding new content that is based upon either new ideas, or cut content that never made it to the game's release back in 2005 and the subsequent releases of the three booster/expansion packs. Other goals of this modification are to modernise the game's visuals by adding various new effects, textures and lightmaps; to expand the co-op and singleplayer experience by adding bot support for all map layers, and lastly, to add new and innovative content that will improve upon the general gameplay and appearance of Battlefield 2, while staying true to the game in its vanilla state. - TheObscure
Okay, so what you see here should be pretty self-explanatory (that is if you know the graphics of BF2 fairly well). If not, let me explain.
Battlefield 2 makes use of shadows that are divided into two systems:
1. Dynamic shadows.
This is used on most of all dynamic/moving objects such as soldiers, vehicles and commander assets. The shadows are rendered while playing, and aren't fairly soft on the eyes like what you can see on newer games such as Battlefield 4. They are also pixelated and the draw distance is poor (although it is increased to the limits in this mod). Lastly, these shadows are very limited and was intended to be drawn on only moving objects (hence, calling it dynamic shadows).
2. Lightmaps:
Due to this game being old as it is, back when it was developed the average system couldn't handle and entire map being rendered out with the same type of dynamic shadows explained above. It was too taxing on the graphics card and was therefore left to another system called lightmaps. These shadows are pre-calculated shadows that are overlayed on the terrain and static objects like buildings as a texture. This means that it could be rendered in advanced software such as 3DS MAX in a much higher resolution. By default, the terrain lightmaps are 4096x4096 in resolution that stretches across the entire map, which isn't a lot if you take the large scale of the map into consideration. Now because I have much more control over the lightmaps and access to 3DS MAX, I will render the shadows at more than twice the size that will give much better visuals.
nice