Выдержка из оригинальной справки. (NDL Gamebryo 1.1)
Projected shadow maps are very similar to projected light maps except that when projected shadow maps overlap they become darker. This behavior makes for more realistic shadow-to-shadow interaction. Like light maps, projected shadow maps come in both perspective and parallel varieties (for limits specified on those lights, please see the section on Projected Light Maps).
· They are specified by placing an image in the Shadow Map slot of a Direct or Spot light.
· Using a Direct light will result in a parallel projection, while using a Spot light will result in a perspective projection.
Gamebryo does support dynamic projected shadow maps (e.g. the shadow of a moving character is computed and cast onto the floor) but they cannot, currently, be created in Gamebryo 3ds max Plug-in. Therefore, to check to see if something is correctly displayed, you will have to get your programmer to enable dynamically-computed projected shadow maps.
PlayStation 2 developers should note that projected textures (light maps and shadow maps) are greyscale by default, and use the alpha channel of the source texture as the greyscale map.
A projected Shadow map example that ships with Gamebryo
Shadow Maps vs. Light Maps
Projected shadow maps and projected light maps will give identical results in situations where they are being used with only a base texture and vertex lighting. They will only appear different when used with additional multi-texture effects (esp. other projected shadow maps).
