What i meant by useless, it's that, rpgmaker, is not suited for it... as we can see it's the basic demo lvl,
1st thing: the map .. is not build within rm, so, you'll need a irrlight map editor anyway...
2nd thing: there are much better 3d games engine quite cheap, which include there scripting language ( often lua ) in addition to C++, like torque, ogre, darkbasic, and other that i forget.
3rd we don't see a mix of both things in this demo, that would maybe mean, that you can't use RM possibilities and the irrlight ones at the same time.
It looks cool, but it's not "usable" for a rm user, or a common scripter. As it would require here advanced math(3D is so much complicated) to make stuff, and advanced 3d programming.
Secondly, the way it's used,
RM, doesn't support "require" for a extension written in c, and directly use the functions from it in ruby...
it needs to go through the win32api to call a function from the dll, with complex arguments...where it'll be hard to use data from rm to the 3d engine or in the other way.
it's not good to force yourself to use rm for everything when there is better elsewhere. try to open your minds to other stuff...if you want to be good. I'm not saying rm is crap, but that it has its limitations.
If you want to make a 3D game, just don't use RM...