This first examples are Ambient + Diffuse + shadows + textures.
Note the last example. The occlusion is correctley portrayed even at multiple distances. The wires from the pipleine occlude only against the pillars (not the sky or other wires). Objects closer to the camera also occlude without unwanted bias (and objects very far away). Also notice how deeper occlusions are darker, in all these examples I super saturated the ambient result to highlight the ambient occlusion. This can easily be modified for a more realistic level of AO in your game. You can also reduce the "radiosity exposure" to increase the amount of gradation between deep and shallow occluders (again, I set the exposure very high so that all occlusions would be considered very "deep").

good night - Michael H Auerbach -