To decorate surface of terrain thematic textures are used. It is supposed that observer is not often interested in the exact photographic information about the wide areas covered, for instance, by forest, water, etc., so that the benefits of photographic texture can be obtained by composing a number of patterns called "themes" to produce a final texture of the specific area. The goal of using thematic textures is to abolish the need of the global area texture, and additionally, animation features become available by simple means
