hi,
I have a game using box2d for the physics,
I try to make a deep copy of the b2World (only the body, I dont have any joints),
so I loop in avery body and I copy them, inside the body I loop in every fixture ……
that work but I have a problems, when I make a step of my copy of world some collision are missed,
I look deeper for see what happend and the problem is the collision are test with my moving object and the static object who were closed when I copy the world but the list of pair in the contact manager of the new world never find the new object close, is well update but and the aabb of every object are good but he dont find the new close object,
any of you already have this issue ?
or did you know what is important to copy in the contact manager (for now I copy nothing, because I was thinking is better to create a new one, and he will find all the contact in the first update ) .
or any other idea ? 
thanks