One interesting thing I found out about Baldurs Gate is it uses reduced bitmaps to store the data for its light maps, search maps and height maps. What they do is make a copy of the original map then grey scale it and divide its width by 16. They try to make the height roughly equal to the width but this is usually off by up to 8 pixels. Sometimes less sometimes more. After it has been reduced they add in the relevant data using Photoshop. What I don''t understand is why they would try to make these data maps roughly square. The large maps are usually rectangular shapes that are wider in the width. I thought this might be an optimisation for path finding. If it is why would a roughly square grid be better than a rectangular one?