This was actually a real-time test of the Unreal Engine, created after we shipped Area 51. This corridor was originally created by Blur studios for the pre-rendered intro cinema. As a challenge, we decided to see if we could get it working in real-time. The geometry and textures had to be re-created from scratch and this was about 3 weeks worth of work. However, having the original meshes and textures from Blur made the process go faster.