Just about everything is faked in cg, but in my experience with Vue, Carrara, Modo and Lightwave, I’ve come to expect that proper GI should stem from the lights in the scene. If you have an interior shot and you put lights in the lamps of the room with GI activated, you will have global illumination. In Poser, there is IBL. I can see that IBL can create a GI-like effect if you use a light dome photo that will generate multiple lights. However, if you light a room with one IBL light and expect it to bounce around and create realistic lighting like it would with genuine GI, you will be disappointed. 

 

Poser 8 doesn't seem to have lights capable of radiosity or genuine GI. 

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