Short explanation(Bad explanation?):
You project the vertices of both boxes onto the boxes unique planes and check if the projected vertices overlap.
Gamedev discussion here-> http://www.gamedev.net/community/forums/topic.asp?topic_id=201240
You project the vertices of both boxes onto the boxes unique planes and check if the projected vertices overlap.
Gamedev discussion here-> http://www.gamedev.net/community/forums/topic.asp?topic_id=201240