Since the map files will be read into the 3d engine directly I think that is entirely up to you, use whatever format suits your code , I am concerned only with graphics at the moment. I have started work on distance darkening (DD), and it works great, depending upon how fast I can generate color matrices we can get some good effects here. If its too slow to generate them on the fly then I'll have to have a buffer of colormatrices and select an appropriate one.

I think I can save some time by optimising the surfaces I'm are drawing to. Use a few SetStyles() to drop some default options. May increase rendering speed a bit.

I have tried fiddling with Bitmap.LockBits(WriteOnly) but it seems to prevent drawing rather than accelerate it. MSDN is no help on this subject.

I'll be back to coding it the main graphics engine again tomorow, I'll take my DD code to work and incorporate it into the engine.