The game doesn’t use true isometric projection. The camera’s image is actually vertically compressed a little bit so that each tile’s width is exactly twice its height, instead of height*sqrt(3). This allows each tile to have power-of-2 dimensions for easy uploading to the graphics card.
Link to the calculator: http://www.niotso.org/zbuffer/
(Use the arrow keys)
Meanwhile, I’ve been working on IFF reading support. I’ve just made a basic command-line utility, iffexport, to extract all of the chunks from a given IFF file. My next task is to learn all of the chunk formats and document them on Niotso Wiki.
I haven’t started chunk-parsing yet, so at the moment the only screenshots I can offer are catalog thumbnails, which are stored in plain BMP format. See below: