3D graphics .obj files

[AMANNE]

How do I use 3D graphics .obj files created with UDK in a C++ project?

[myclone]

You could use a library like libobj or Assimp or the Wavefront (obj) loader.

http://people.cs.kuleuven.be/~ares.lagae/libobj/index.html

http://assimp.sourceforge.net

http://www.kixor.net/dev/objloader/