The engine supports two types of terrain, chunked or unchunked. Which type a terrain has is determined by the terrain_chunk variable or by a '_' at the second-last place in its file name (e.g. "nonchunked_n.htm").
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Chunked terrain is split by the engine into square chunks whose size is also given by the terrain_chunk variable. It is rendered as a stream of chunks that are separately clipped when outside the view frustrum. This allows for faster rendering and unlimited terrain size. The catch is that a chunked terrain can't be put multiple times in the level, and can't be deformed because its vertices can not be directly accessed. Unchunked terrain is rendered as a whole, uses less memory, and vertex deformation functions can be applied, but there's a size limit of 256x256 vertices per terrain.
