I wanted to post about my project, since people on here might really like it. Previously it was using the TrueVision3D engine and then the Crystal Space game engine, but the transition to Ogre was done in late 2010/early 2011, with Crystal Space itself being discontinued around 2012. Currently it's using Ogre 14, and is now in beta, preparing for a 2.0 stable release.
Skyscraper is a first-person 3D virtual building, elevator, and city simulator, written C++. Development started in December 2002, 1.0 was released in 2004, and the C++ version of 2.0 Alpha started in mid 2005. The sim engine itself is called the Scalable Building Simulator, or SBS. Buildings in the simulator are written in a custom scripting language inspired by the old TrueVision3D engine, and cities are possible by running multiple sim engines (each a building) in parallel. I've been working hard on trying to modernize the project, and am looking for anyone interested in helping develop it, if they find it interesting and are good at C++ and somewhat with Ogre.
Main website: https://www.skyscrapersim.net
Custom addon repository: https://custom.skyscrapersim.net
Source code: https://github.com/eventhorizon5/skyscraper
Also check out the forum, and discord server, links are on the website.
First-person 3D interiors, this is the Sandy Spire building by Skyscraper Simulator Showcase:
Virtual cities (the only city size limits right now are available RAM and sim engine context switching):
Working elevators (controls such as inspection service even work):
Working escalators:
The 138-story Glass Tower building, from the movie The Towering Inferno, based on original production blueprints:
The detailed Glass Tower roof, with rooftop elevator and helipad:
VR support was recently added, it's still an experimental feature though, and requires movement via keyboard, not the hand controls yet.
Youtube video demonstrating one of the user-created buildings: