GI_Joe simulates Global Illumination (GI) by putting a sphere of spot or directional lights around your scene. There are quite a few threads on this in the forum so you might want to check through the topics of older posts (if you can't find it via search, choose to view all threads "from the beginning" at the bottom of the page and you can glance through the topics). This thread should get you started if you decide to install it and try it out:

https://forum.simplymaya.com/showthre...&threadid=3533