Boolean union fails while intersection looks ok


again boolean trouble.
I can’t find anything wrong with the intersection…

NoBool7.3dm (796.0 KB)

Doesn’t work in V5, and not in V6.


I haven’t looked into this very closely but just opening this file in Rhino 6 and hiding the curves, then intersecting the two objects gives me this:

and obviously, this won’t boolean. Did you do something to the tolerances before / after getting your intersection curves?

Oh, that is ugly.
And of course this won’t bool.

In V5 the intersection is complete and closed (see file).
I did not play with the tolerance.

This means, in V6 it is even worse…
A good reason to find out what’s going on.


On an other PC, I now get the bad intersection result as well in V5.

Edit 2:
I have different Service Releases on the PCs.
One is SR12 (Updates & Statistics say most recent).

The other has:
Version 5 SR13 64-bit
(5.13.60326.15590, 26.03.2016)

Must have been the most recent one someday.

Hi @Charles, move the pipe part in positive y direction by 0.0005 millimeters and it should work. Btw. why angle tolerance of 3 degree ?


Hello Clement,

I don’t need a solution, I know how I can get a result somehow.
Instead I want to show an existing problem.
And I want to understand the nature of the problem.

That’s the template default.
You are right, that is a bit coarse.


Hi @Charles,

the source of the problem seems to be a bad parameterisation of the piped part. You can get away of that without moving the part by doing this:

  1. _Explode the piped part
  2. Use _Reparameterize 0 1 0 1
  3. _Join

Now just do the boolean and it works. Btw. did you use _SrfSeam on some of the pipes ?


Hello Clement,

Aha, I would not have had this idea.

No, I didn’t use _SrfSeam.

Leads to the next problem:
What causes _Pipe to make it like it does?


Hi All - thanks for digging into this - @clement, good catch on reprameterizing - Automatic does not work, but 0-1 does…I’ll send this to the bigger brains.


This is fixed for the next WIP. There is still a problem with Intersect. Depending on which order you choose the objects, Intersect will either get the full curves or miss some pieces.

RH-38416 is fixed in the latest WIP

Hmm, I don’t see any difference.
Intersection is as expected regardless of the pick order.

Yes, it is - very good!


I get the same result as Wim, in his post above, if I pick red then blue. The other way I get the correct curves.

YesBool7.3dm (5.1 MB)

worked with an absolute tolerance of 0.1, got a message tolerance had to be doubled for it to work.

Hi Richard,

In the last V6 WIP, it works also with 0.001 tolerance.
No need to mess with the tolerance no more.

I think there won’t be a solution for V5…