How to Close an Open Polysurface!

Rhino Rhino for Windows
1

Cannot close this polysurface. There is a naked edge at the very fore part of the hull. Can anybody help me?

Untitled.3dm (151.1 KB)

2

Hello -

  1. ExtractSrf the top, deck, surfaces.
  2. Turn on control points for the deck surfaces.
  3. Window around the ones near the very tip.
  4. SetPt snapping to the end point of the top edge if the hull - zoom in to make sure you get the very top, there are some short vertical edges that might grab the End Osnap
  5. ExtractSrf the short vertical surfaces and MergeAllEdges.
  6. Join.

Any luck?

-Pascal

1 Like
3

That’s because that is a lousy way to make the deck surface. Even if you get it to work you still have a degenerate surface that may cause additional problems.

Its much less likely to cause problems if you make the deck as a trimmed extrusion
deck.3dm (137.0 KB)

1 Like
4

Well you can select the top part by using Shift + Ctrl and selecting it, then delete it,
now from Surface menu choose Edge Curves and select the 4 top edges and Enter, that should close it

I’m editing the post because of one missing step:
After deleting the top part and before using the Edge Curves command, we need to explode the whole
Body then Join it again. This step will fix small errors in the body. After this, the Edge Curves will leave no
naked edges.
Untitled_fixed.3dm (307.9 KB)

5

Hello Pascal,

Could you please help me? I am a beginner at Rhino and I cannot fix the problem although I applied your steps. Here is my window sample. As you can see, there are some weird areas close to the corners.

image
image991×806 51.4 KB

or here is the rendered mode:

image
image867×769 233 KB

And I also attached the 3dm. file.

Thank you in advance. I’ll be looking forward to hearing from you soon. :pray:t4:

Pinar Aksu

window_sample.3dm (321.7 KB)

6

@aksupi
Your model is more than 5476 KM away from the origin ! ? Any reason for this?
If you move the object close to the origin the artifact will disapear. Anyway the reason for the artifact is something to do with floating point precision…

7

I don’t understand. I didn’t do it intentionally, but I think now it is on the origin. Is it? However it still has that weird part… Do you know how can I fix it? :pensive:

window_sample2.3dm (333.9 KB)

8

Hello - select the object, start Move and snap to some location on the object as the From point. Then as the point to move To, type in ‘W0,0,0’ and Enter. Then Zoom Extents.

Then RefreshShade to finish.

Any luck?

-Pascal

1 Like
9

Oh, thank you so much! :pray:t4: :heart: It worked perfectly.

Best wishes,

Pinar

10

Hi Pinar - OK, good - more info here:

-Pascal

1 Like
11

Hi Pascal. I’m having a similar issue with this bench I’m designing. I have attempted all different ways to resolve the naked edges that are still an issue in this model. I need to split this into 3" pieces to get CNC’d but I’m unable to do that until I can close the model. Can you offer any advice on how to close the edges that are naked?
bench_naked edges.3dm (429.7 KB)

12

Hi Chris - the object has some bad surfaces - I am not wild about how you closed off the top surface here:

image

I’ll see if I can suggest a better way.

-Pascal

13

Thanks Pascal. Any luck here? I’m not sure why the NetworkSrf command is giving so much trouble here. Any other recommendations on modeling this condition?

14

Hi Chris - yes and no - I can point out what I think is a better way to build this thing overall:

1, Make all the simple, exact, and over-sized, primary surfaces - looking at one half here:

image
image953×621 36.8 KB

  1. CreateSolid (note you need the vertical center plane - that will be removed later

image
image1080×646 28.2 KB

  1. FilletEdge the verticals -

image

image

image
image1173×717 45.3 KB

Then FilletEdge around the top -

image
image1041×1002 108 KB

That is a good way to go, in general, I would say, the problem is that in that last variable fillet operation in this case, Rhino is making a mistake and I have not figured out why. I’ll see if I can sort it out.

-Pascal

5 Likes
15

Hi,

I think I have a similar problem as above, and I have tried all the mentioned steps. As Im going to send the model to a 3d printer it needs to be one closed polysurface. Any more tips on how to close open polysurfaces? I cant attach the 3dm file since the filesize is too large. Is there a way to find where the polysurface is open?

/Elsa

16

Hi Elsa -

You can use the ShowEdges command to show naked or non-manifold edges. You could also use the DupBorder command to create curves on open edges.
-wim

1 Like
17

Hi,

Thank you for the help.

When I use the ShowEdges command on the object, no naked edges show, but it is still an open polysurface. There are a few non-manifold edges though, are they the problem?

/Elsa

18

Very likely.

19

ok, but then is there a way to solve the problem of the non-manifest edges so that the i can make the object into a closed polysurface?

21

You can put the file into a ZIP or RAR archive and upload it here. That will make it considerably smaller in size. Alternatively, you can upload the 3dm file on Google Drive, Mega.nz or another reliable place for free hosting.