An example :
Each 'thing' has an influence score (a tank has 5 pts, a jeep has 2 pts). This score halves (or whatever) each grid from the object.
So the tiles surrounding the jeep get a score of 2.5.
The influence of friendly units is added and the influence of enemy units is subtracted. This results in a figure showing how under control a tile in the map is.
It doesn't have to be attack/defence. You can influence maps for lots of things... where to build houses (roads, rivers have +ve, mountains, swamps have -ve.)
This has some good links.
Each 'thing' has an influence score (a tank has 5 pts, a jeep has 2 pts). This score halves (or whatever) each grid from the object.
So the tiles surrounding the jeep get a score of 2.5.
The influence of friendly units is added and the influence of enemy units is subtracted. This results in a figure showing how under control a tile in the map is.
It doesn't have to be attack/defence. You can influence maps for lots of things... where to build houses (roads, rivers have +ve, mountains, swamps have -ve.)
This has some good links.