Thanks Ralf for you answer.

I tried to upload the file, but I get a 500 - Internal server error... maybe is too big (is a house).
Anyway, is not worth to find the problem in this particular situation.

What is more important for me is to understand if I'm doing something in a wrong way, not to do it again, or if is just a little problem of the boolean that I will have accept.

Thank you very much again

Eugenio

Hi Eugenio, is the whole house one single solid?

In order for the booleans to produce a new solid, they have to create a well formed intersection curve between the objects being booleaned, the intersection has to be closed and not have any self intersecting loops. If there is any difficulty in getting that type of intersection then that can be one way that you'd get a "Joined surface" result. There are various different situations that could cause that, like if some surfaces have any self-intersections where the surface folds back over itself or also if there are 2 surfaces that barely skim over each other with overlapping surface area that can make for a sort of meandering complex intersection curve. So if you have something like that it can help to make the pieces push through each other a little ways instead of having shared surface area, although if it is a very exact case with overlapping planes that's usually ok.

It's difficult to know exactly what your case is without seeing the objects, if it's just 2 smaller objects in your model you can select just those and use File > Export to make a smaller file with just those objects in it to upload, or otherwise you could use a file sharing service like Dropbox to host your file and then just post a link to it here rather than making a large attachment directly here in the forum.

- Michael

Hi Michael,

Thank you for you answer

I export the 3 solids and attached them to this message.
Anyway you already have explained to me why this may happen, which was what I wanted to know, not to solve this particular situation.
If you can easily see what is the problem in this solids, I will appreciate it, but please don't spend a lot of time in this, it don't worse it.

Thanks you very much and good luck with V4

Eugenio

Hi eugenio,

Well that's a funny one, because I can't find any naked edge after the boolean etiher.

I don`t have an explanation, but a quick fix is to separate and rejoin every surfaces, you should get a solid after that.

Hi PaQ,

Thank you for you answer.
The next time something like this will happen I will separate and rejoin the surfaces maybe is the solution...

Eugenio

Hi Eugenio thanks for posting the file. So I couldn't see anything wrong with your model so I took it into Rhino to check it in there too and then I was able to see the problem is with this particular edge here:



Some other underneath views of it:





So it's something like this where there are 4 surfaces all touching along that one single edge:



So that's what's called a "non-manifold" edge, and it can cause complications for determining the proper inside and outside of a solid volume. It's kind of like a zone of zero wall thickness and if something tries to intersect that edge it won't be clear to it which side it's happening on. It's similar to the problems caused if a surface intersects itself, in this case it's like the "skin" of the solid is intersecting itself.

That looks like the only spot with that problem.

- Michael

Hi Michael

Thanks for using your time to find the problem.
This kind of edges sometimes appears to me after some working with a solid (extrusion of faces, booleans...)
In any case, is not critic, I only wanted to know if I was doing things in a wrong way.

Eugenio