Hello gentelmens

So im truing to make some ribs on a bit complicated shape.
In the start the ribs was just a planes with "Shell" applyed.
After i trim those ribs by main body and make boolean union.
The first two ribs - doesnt make any trouble. Im even able to make a fillet.
But second two doesnt union, instead of this they just leave partially cut on main body.

How this can be solved?

Hi Alex, can you please post the model or if you want to keep it private you can e-mail it to me at moi@moi3d.com .

If you could send it in the state before doing the booleans that would be good.

Thanks, - Michael

I send you model, Michael.

Im mostly sure what entire model till the bolean operation probably was have some errors/misunderstanding of correct pipeline from my side. But anyway its a bit wierd what boolean was working in one part of the model, but fail in other.

If someone intheresting, feel free to download and test it.

Hi Alex, I sent you a reply through e-mail, copying here too:

Thanks for sending the file. It looks like the problem is some of the ribs are not solids. Like the one in the attached screenshot:



has an object type of “Joined srf” instead of solid. That means that there are some “naked edges” in it – edges that belong to only one surface instead of being joined between 2 surfaces as a solid will have.

The boolean operations will intersect objects and then determine which areas to keep and which to discard based on which solid volume they are contained inside of. The results can be unpredictable if some areas are not closed solids.

It’s not very good to make pieces to boolean that have coincident surface areas that are just barely skimming over top of each other. For ribs like this don’t try to cut the rib down and then union the piece that is skimming along the interior, instead use just one boolean union with the “boolean subset” function. That’s where instead of selecting the whole object you should instead select only the interior faces of it and then the boolean will only intersect using those faces.

See here for some examples:
http://moi3d.com/forum/index.php?webtag=MOI&msg=6793.3
http://moi3d.com/forum/index.php?webtag=MOI&msg=6742.10
http://moi3d.com/forum/index.php?webtag=MOI&msg=6663.1

Here’s a screencap showing what you would select for your object, the Booleans will work better when the pieces that are to be booleaned push through each other a ways instead of having skimming/overlapping surface areas. So notice here that before doing the boolean I have selected only the interior faces of the main object. That will limit intersections to only be calculated on those faces and not in other areas:




Hope this helps!

- Michael

Thank you Michael!

I forgot about those feature of selective union!
And i also was quite sure what ribs pieces are all solids, just because first of them was union smoothly without problems.
Limited union works perfect and create pretty clean and "solid" lines there ribs are connected.