I noticed in some graphics scenes that there are too many buildings far away (the player never get there) for example the player is over brooklyn bridge, there are TOO many buildings around, but he will not get there by any chance.
I believe (probably) that those are not real buildings, is there is any way to create buildings illusion? (Since the player will never go there I just want to the player to SEE them).
Those sort of things are almost always modeled at a much lower level of detail relative to the geometry that the camera will get close to, which means less polygons, small textures, and fewer draw calls. It's also common to use forced perspective to make the models appear much further away than they actually are.
@Medo
Most games have console command line systems, so you can use cheats to explore inaccessible areas of the maps and see for your self how it is done.
@Tom KQT, cozzie: What If I'm using skysphere instead of skybox?
@belfegor: Nice idea!
Those buildings could be fake, or if they are far away they could be 3D, but incredibly low polygon. If the buildings are very small from that distance, you can get away with very low detail buildings, rendering hundreds of them with only a few thousand triangles. You can also have them be in the same model and use a single texture. From that distance a building side might be just a few texels wide and you can determine optimal mip levels if you can't get any closer.
You can have a ridiculous amount of low poly static objects with very simple shading in a scene:
