> Ps like the volume "the wall + windows" above, does exist a reasonable limit of the numbers of
> windows(objects) to booleanize ?(difference) (one by one or all in a same pass)

There isn't really any fixed limit... Sooner or later it will start to slow down but you should be able to do quite a lot of them, I think.

- Michael

Ok I understand this problem of "topology" (?) thx for the explanations!
< So for instance, to remove a window, don't create a box - instead select the side pieces of the window and delete them. Then select the open edges of the window and delete them too, removing the hole - now the window is erased and the original surface is restored in that area. You can only delete edges if they are not attached to something else, so that's why you delete the side pieces of the window in a first step.

You say "side pieces" it's well the "sides faces" not the "edges" side? (due "only delete edges if they are not attached to something")

I have delete the "faces" side prime and that works :)
But something will be very cool in this case (and useful in many other cases of course) : a "loop (or ring) selection" faces (or edges) :)
Is that possible?

@Schbeurd : You see I take heed of any informations :)

Yes, topology is it exactly!

> You say "side pieces" it's well the "sides faces" not the "edges" side?
> (due "only delete edges if they are not attached to something")

Yes that is correct, the side faces must be deleted first. This leaves open edges and then the open edges can be deleted.

But I just realized that there is a bug that if deleting the edges causes the object to become a fully closed solid (like in this case), there is a problem with the structure of the object which may interfere with some operations like booleans. The problem will be solved if you save the file and re-open it though. So until I get a chance to fix this bug you may need to save the file and re-open it after you delete holes in this manner.

Otherwise you may notice some strange problems like booleans not handling the interior parts of objects properly.


> But something will be very cool in this case (and useful in many other cases of
> course) : a "loop (or ring) selection" faces (or edges) :)
> Is that possible?

Yup, it was part of your previous list! Sometime after array and image planes are functioning.

- Michael