Hi all,
ForumBooleanUnion.3dm (9.2 MB)
I am attaching a model with 3 polysurfaces - in different layers to make it clear - that I am not able to union. I have tried changing tolerances and, given that I am a newbie, I must be doing something wrong.
I am pretty desperate, so any help is more than welcome <3
Hello David,
There was a Surface intersection error (Select the group01 dot after you try the union.).
I exploded the whole model then used the join command twice selecting the whole model each time.
Thank you,
Andy
p.s. Sorry. I did not notice you are using a Mac. I guess the process would be similar? I used Rhino 7.
ForumBooleanUnion_.3dm (4.8 MB)
Thank you so much! I wish I could understand why do I need to go through that process… but exploding and then joining was the solution.
I really appreciate your help, thank you.
Hello David,
You are very welcome. I believe there is a technical explanation but I am not knowledgeable enough myself to offer the reason.
Thank you,
Andy
Hi David,
The problem is in the left face of the orange piece which is not quite flat, meaning that there is a gap in the middle between it and the green piece. The explode/join/join “works” because the edges of the orange piece do touch the edges of the green one.
Note however that the explode/join/join leaves you with internal surfaces at this interface. These may cause problems in later modelling, so it would be better to fix the geometry and boolean union. (Also note that the explode/join/join has created two closed pieces - the second one being at the ymax end of the red piece).
HTH
Jeremy
Hello Jeremy,
Thank you so much for the explanation and upon just selecting the object I get in properties a single closed solid polysurface and in the command line: 1 closed polysurface added to selection. If I:
Command: '_SelPolySrf
3 polysurfaces added to selection.
Command: '_SelClosedPolySrf
3 polysurfaces added to selection.
_ShowEdges
Found 3523 edges total; no naked edges, no non-manifold edges.
So I am glad you posted your comments. How did you determine the orange piece is not quite flat ?
Thank you,
Andy
Hi Andy,
When a Union doesn’t work one looks at the intersections, so I zoomed in a lot into the first junction between green and orange in the Top view. Whereas the end of the green piece was represented by a single line, I could see several lines for the end of the orange piece. To confirm my suspicions I extracted the end face and checked its details. If it was flat it would be described as a Plane Surface:
Whereas the orange face is described as a Nurbs Surface:
I could equally have run Curvature Analysis on the face.
HTH
Jeremy
Hello Jeremy,
Got it. Thank you for taking the time to show what is going on. I appreciate it.
Andy
