Problem with shadows ?

[dazappa]

thank u Andru

I hope somebody find a solution for the shadows, because the shadows give more reality to the game

For this type of shadowing you really should probably look more into lightmaps and/or baking them into textures. The general idea is to pre-generate how the shadows should look while leaving few objects with actual real time shadows (such as cars, or people). You really should look into breaking up your city model into multiple models, assuming it is from a close viewpoint like first person.