Map shaders take a “snapshot” of the scene at the moment it is rendered, and applies it to an object as a texture.
Map examples A. Created map B. Scene with the shadow map applied to the floor plane.
Map shaders is a useful alternative to live shaders as they do not demand much of the system’s resources to display.
Map shaders are used when the environment surrounding an object does not change. In the figure above, a map shader is used to portray the shadow cast by a chair; as long as the chair, the cast light, and its environment are static, the shadow map is appropriate.
If something crosses the path of the light beam, it does not cast a shadow. You can combine Live Shadow shaders with map shaders in the same scene to save system resources.
That way the light in a scene cast by a sun or lamp never changes by the shadows cast by the animated character does.