A few pics generated by the "Quantahawk" engine I've put together. It is meant to be a versatile tool to rapidly generate real time environments.
You can browse for models and scripts at run time. So far it can set up the following by script:
Load X file mesh models
Initial alteration of world space scale and location.
Hierachical position and orientation of mesh objects.
Real time dynamic shadows.
Point sprite particle systems.
Vertex tweening mesh.
Alpha sorted axis and full billboarded Quads.
Pre and Post render states for individual geometry.
ray-mesh collision detection.
Script driven programmable dynamic orientation
Simple "Perlin Noise" terrain generation
Spherical environment mapping for quasi-reflective surfaces
Set center of gravity
Replace xfile textures with others
Gravity, collsion detection, Keyboard& mouse navigation modes can be toggled at run time. Lighting can be altered at run time. There is the beginnings of a user interface that uses quads in camera space with ray-mesh collision detection for buttons. Although there is not many sound effects at the moment you can apply FX like echo, distortion and reverb to wavs.
You can get an .exe and some media from my web site www.labyrinth.net.au/~mstephens
I would be happy to discuss any ideas with like minded individuals.