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System error during meshing

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Old   October 11, 2006, 05:48
Default I got a very complicated geome
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ares_tum
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I got a very complicated geometry (no warning or error when imported by netgen), which is being meshed by netgen now. The meshing takes at least 2 hours, but still around 99.8%. It shows in the command window that:
"System error: hash table si not fitting for segment: ..."
Does anyone know what's the problem?
Thanks in advance.
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Old   October 11, 2006, 05:51
Default sounds like you ran out of mem
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Hrvoje Jasak
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sounds like you ran out of memory: this must be a pretty big mesh!

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Old   October 11, 2006, 06:03
Default This is the model.
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ares_tum
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This is the model.
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Old   October 11, 2006, 06:06
Default Here is the model, could anyon
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Here is the model, could anyone try to mesh it?
Thanks
stl.zip
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Old   October 11, 2006, 07:53
Default There are a lot of intersectin
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christian_hausmann
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There are a lot of intersecting elements in your model.

Can you change the settings of you CAD program to get a better stl-file?

Netgen needs a almost perfect geometry to finish meshing.
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Old   October 11, 2006, 08:10
Default Thanks for your answer,Christi
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ares_tum
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Thanks for your answer,Christian.
The original model is downloaded from internet. I just cut one part out, and added a top onto it.
Could you please tell me where do the intersecting elements locate? On the top, bottom,or lateral surface? How to solve it?cad?
Thanks
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Old   October 11, 2006, 08:48
Default They are spread over the hole
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christian_hausmann
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They are spread over the hole surface. Use a CAD program. Try to vary the features of the stl-export-function. (more accuracy) What's you CAD program?
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Old   October 11, 2006, 09:25
Default I think i can see them now in
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ares_tum
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I think i can see them now in netgen. Really a lot. I am not familiar with cad and don't have any cad program in my computer. Are there any other possibilities? Or i have to modify them by hand
Thanks a lot.
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Old   October 12, 2006, 04:18
Default You can try to use the stl-doc
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christian_hausmann
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You can try to use the stl-doctor.

Change "Double Click selects:" to "triangle" and select one blue-edged triangle, or Deselect "select with mouse", Insert the number of an intersecting triangle below.

After selecting an intersecting triangle use "move point to middle of trianglepoints". Maybe 0-volume-triangles were generated, delete them. Save the geometry.

Be sure that you exclusively insert the number of an intersecting element. Select an triangle with mouse is not always as easy as it seems.
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Old   October 12, 2006, 05:14
Default Great thanks, Christian. I'll
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Great thanks, Christian. I'll try it.
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Old   October 30, 2006, 14:37
Default Hi Zhengxiong, I had a look
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Philippose Rajan
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Hi Zhengxiong,
I had a look at your STL file in Netgen, and tried a moderate mesh generation... Here is a screen-shot of the result I got... I have marked in red the areas (there are more on the rear side), where Netgen is having trouble closing the mesh due to inconsistent and intersecting triangles....

As Christian Hausmann suggested, I think you need an STL export with finer triangles defining the surface....



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Old   October 30, 2006, 14:40
Default Oops.... Looks like the file d
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Philippose Rajan
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Oops.... Looks like the file didnt get uploaded... second try :-)



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Old   October 30, 2006, 14:45
Default Looks like Firefox in Linux fo
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Philippose Rajan
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Looks like Firefox in Linux for some reason doesnt support this possibility of uploading files.... any suggestions from anyone ??

Sorry for flooding the message board :-)!

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Old   October 31, 2006, 13:56
Default Hi Philippose, Just a test
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Mattijs Janssens
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Hi Philippose,

Just a test to see if the uploading works from konqueror. You are aware of the 50k limit?

unitCube.stl
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Old   October 31, 2006, 14:55
Default Hi, 50k limit :-)!! Oh my...
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Philippose Rajan
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Hi,
50k limit :-)!! Oh my... no wonder... its all clear now :-)! The image was 450Kb... but well, with some Gimping and rescaling, I have it down to 12.5Kb... lets see if it works now :-)!




Thanks for pointing out the limit Mattijs :-)!

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