D'Oh!
If you'd asked a year ago, I'd be dying to. I was designing a axonometric (like isometric but you can freely rotate) 3D engine for RTS type games of my own back then, but it got shelved. I even put some shots in the misc amiga images here.
Actually, the engine didn't get shelved itself, the C++ portability libraries I created upon which it was built got shelved. I have since been building a much cleaner, more powerful set of libraries but haven't implemented everything I need to in order to start such a project again.
For the forseeable I will be very busy with other work but I have always intended to restart that project from scratch at some point.