Ability to render overview images

[Cameron-D]

The ability to save a high-resolution top-down image of the entire loaded world would be very cool, the output would look something like these:

http://www.nextdimension.org/bmrf/Black_Mesa_Research_Facility_HL_Map.jpg

http://www.unleashthedog.net/uploads/HL2_overview.jpg

[w23]

The feature itself technically is trivial and implementing it would take me about an hour or two, but making that image pretty is a real challenge. There are too many glitches (misplaced "appendix" geometry), materials support is incomplete, maps intersect in weird ways, topmost layer is not guaranteed to be recognizable from the gameplay and so on. The referenced images are cool (thanks for sharing!), but apparently hand-crafted, and automated solution wouldn't be as nice.

I think I'll make the first necessary technical step when I get some free time, and then we'll see.