Have a look at Mapbuilder. I'm using it at the moment, and it is pretty good. The gui takes a bit of getting used to but the support is excellent. The address is http://www.skydat.net/MapBuilder/index.html
Have a look at the demo. It is possible to import straight into Blitz3D, but you need the registered version for it.
Have a look at the demo. It is possible to import straight into Blitz3D, but you need the registered version for it.