Irrlicht Engine

I don't need the specifics (like code) but just enough to get an idea how it is done in Irrlicht.

Thanks.

That's far too vague to be answered here. Build a room? How do you want to do it? From blocks, in one big mesh, in levels? In any case you are going to need something like Milkshape because Irrlicht views meshes, it does not create them ( although it is possible to create meshes in Irr manually, it's good practice to hard code as little as possible )

Yeah, to make a room, you can use any 3D-editor that can export to files, supported by Irrlicht (see FAQ page...) As for me, i prefer Anim8or, it's very handy and it's completely free...

OK, out of polygons...

Use a 3D editior.

www.wings3d.com is free but can only model - not texture or animate (yet).

Milkshape is a good allrounder.