Question about boolean compounds

[ernestochirinos]

Hi..
I've a question about using boolean compounds. Im starting with 3DStudio so maybe this is a silly question..

I have two boxes, same size, and put one besides the other.
Then I attached them and weld vertex of the contigious faces. (Object A)

When I use another box (Object B) and put it between the previous two boxes of the object A (to do a boolean compound A-B).. the Object B cut perfect one of the boxes of the Object A but not the other.

If i dont weld the vertex making the Object A, and only left the boxes attached.. the cut is made perfect in both boxes..

Could anyone explain me this?

 

[KBBJ]

So good question!
You have to unify the normals before 3dmax will see it as one object.
I asume that you have made the 2 boxes into 2 meshes before attaching and welding them.