Here is nice article explaining some of the techniques the author used to setup a nice 3D virtual city flash project.
Futuristic city, 3D techniques in Flash
About the Author: Carlos Pinho
A father, a husband and a geek... Carlos was the founder of projects like The Tech Labs and Flash Enabled Blog. He is the founder of TekTuts He is passionate about technologies. Their main skills are in analytics, transport & logistics, business administration. He also writes about programming resources, trends, strategy and web development.