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.STL: non-closed manifold surface

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Old   October 28, 2013, 06:05
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Hey,
i've got similar problems to giulio. My biggest problem is, that my stl file is not closed and i get pretty bad snapping at the edges.
I tried to repair/clean my stl with Meshlab but without big efforts.

Perhaps you could have a look at my stl. The geometry will be used as a pipe streaming through the big patches.

kanal_original.txt


Greetings
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Old   November 2, 2013, 14:39
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Greetings Phil,

I had a look into your file and here's what I got:
  1. surfaceCheck indicates that there are 8 unconnected regions:
    Code:
    surfaceCheck kanal_original.stl
  2. The reason for this is shown in the attached image, namely that not all vertices are connected to other vertices.
Therefore, it's as good as there are surfaces floating surfaces, when it should be a solid.

As for fixing it... in Meshlab, you can use from the menu "Filters -> Remeshing, Simplification and reconstruction -> Delaunay Triangulation". I wont be a perfect triangulation, but at least it fixes the problem

Best regards,
Bruno
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File Type: jpg kanal_original.jpg (35.0 KB, 98 views)
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Old   February 27, 2015, 03:37
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Hi,
may I also ask sth regarding surfaceSubset?
I have copied the surfaceSubsetDict and try to run it for my case but I get the error

Istream not OK for reading dictionary

Any ideas how I can fix this?

Thank you very much in advance for your help!!!
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Old   February 27, 2015, 16:19
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Quote:
Originally Posted by pizzaspinate View Post
Hi,
may I also ask sth regarding surfaceSubset?
I have copied the surfaceSubsetDict and try to run it for my case but I get the error

Istream not OK for reading dictionary

Any ideas how I can fix this?

Thank you very much in advance for your help!!!
Greetings pizzaspinate,

I think I saw a similar thread of yours on this topic, where you then stated that you managed to fix it. But now I see that you asked this here as well.
Therefore, if you've managed to solve this problem, then please indicate how you fixed it.

If you haven't solved this problem, then please provide more details (namely, if you did any modifications to the dictionary file "surfaceSubsetDict"), since that error message can occur in a lot of situations.

Best regards,
Bruno
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Old   March 3, 2015, 05:41
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Hi Bruno,

yeah I posted it twice because in my experience you don't get much responses when you reply in old threads. Sorry for that.
Yes I managed to fix it. I had to enter the command:
Code:
surfaceSubset surfaceSubsetDict UCAV.stl UCAV_prob.stl
in constant/trisurface to avoid the error.
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Old   April 15, 2016, 06:41
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dear wyldKat,

very quickly : i need to fix some .stl files to then use in OF. I have blender.
How to just add a lower cap (as inlet) to this stl https://www.dropbox.com/s/hzgq9l0e72...perta.stl?dl=0 (which is the bottom of my object), so to have one single .stl file which passes the surfaceCheck ? Could you gently post it ?

This old link you suggested here http://engits.eu/wiki/index.php/Tuto...ing_Geometries where is now?

thanks a lot, have a nice day,
i
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Old   April 15, 2016, 18:00
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Quote:
Originally Posted by gned View Post
very quickly : i need to fix some .stl files to then use in OF. I have blender.
How to just add a lower cap (as inlet) to this stl [...]

This old link you suggested here http://engits.eu/wiki/index.php/Tuto...ing_Geometries where is now?
Quick answer: I've updated the link on the post you mentioned and the new link is this one: https://github.com/enGits/engrid/wik...and-enGrid-1.2

And sorry, but I don't have the time needed to fix that STL file, specially because I barely know how to use Blender
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Old   April 24, 2016, 07:01
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Quoting the PM you sent me:
Quote:
Originally Posted by gned
Hi wyldkat,
thank you for the updated link, it has been very useful.
Using different tools, as Blender and Freecad, and operations of cutting/extrusion/filling I got this final stl

https://www.dropbox.com/s/z5tyrv4y2n...y_018.stl?dl=0


It's clean but when you surfaceCheck it, still it splits the external case and the inside poppet in two .obj files (I think just for a different not conform triangulation of the two objects at their border more than for reasons of really non- stitching edges/gaps there).

So which tool or OF surface* utility you usually recommend to obtain a really perfect stl file, still divided in different solids as this one, but which is one unique watertight stl file, before sHM it ?

thanks a lot,

i
Sorry, like I wrote in my previous post, I don't have time to look into this.

OpenFOAM itself doesn't have utilities that will solve these problems automatically.

You can try and use this STL and see if snappyHexMesh can still use it, regardless of the errors.
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Old   April 28, 2016, 08:53
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hi, I've problems using surfaceCheck. And I already used Meshlab and Admesh but it isnot completely removed that problems.
What should I do?
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Old   May 1, 2016, 19:04
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Quick answer: Creating waterproof STL using snappyHexMesh or salome
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Old   October 11, 2016, 10:33
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dear wildcat,
I have 2 simple .stl files representing 2 plates I need to merge together (see pic1), so I proceed doing :
> surfaceAdd solid_1.stl solid_2.stl 2solids.stl

Then I wanted to exploit the problemFaces given in output by
> surfaceCheck 2solids.stl

to eliminate them through
> surfaceSubset surfaceSubsetDict 2solids.stl 2solids_after.stl

in order to have no duplicated internal faces at the merging of the plates.
But actually the problemFaces that OF catches result to be strangely the lateral ones to the plates (see pic) and not the internal faces as expected.
So why this and how I can then obtain a unique .stl which passes the surfaceCheck ?
Attached Images
File Type: jpg pic1.jpg (18.4 KB, 2 views)
File Type: jpg lateral_problemFaces.jpg (25.2 KB, 2 views)
Attached Files
File Type: txt solid_1.txt (1.6 KB, 0 views)
File Type: txt solid_2.txt (1.7 KB, 0 views)
File Type: txt surfaceSubsetDict.txt (2.1 KB, 0 views)
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Old   November 23, 2016, 08:31
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Hello everybody,

to become familiar with OpenFOAM I am trying to run an OpenFOAM case, which is modified from the motorBike case. I tried to replace the motorBike with a sphere that has a diameter of 1 [m]. This sphere is drawn in SolidWorks and compressed to a .stl.gz file. To minimalize the chance of mistakes I have given this sphere the name motorBike.stl, I am using SHM to mesh the sphere, and the blockMesh of the original motorBike case. The SHMDict and surfaceFeatureExtractDict are attached.

The problem I am facing is that the mesh around the sphere isn't visible in paraFoam, or isn't even made at all during the SHM command. I have tried to make the sphere smaller, and also tried to use RhinoCeros to draw the sphere, without any succes. I also tried to change settings in the SurfaceFeatureExtractDict, also without improvement.

My question is if there is anybody that has a suggestion or have been facing a similar problem?

Many thanks in advance!

Best Regards,

Joost
Attached Files
File Type: txt SnappyHexMeshDict.txt (9.4 KB, 2 views)
File Type: txt SurfaceFeatureExtractDict.txt (1.6 KB, 2 views)
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Old   November 25, 2016, 04:15
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Hello again,

I have found my problem..

My sphere has a diameter of 1 [m], so does my mesh have. The centre of the sphere was placed exactly on the centre of 1 mesh cell, so the sphere didn't cut through any cellborder, and for that reason the sphere wasn't visible at all.

My bad! Hope this answer will help people with the same problem.

Regards,

Joost
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