Importing 3D geometry from Rhino

[Daiquiri]

Hello,

I have installed Aurora few days ago and have been trying to import a simple 3d geometry from Rhinoceros without success. I have tried with all types of files Rhino can export: dxf, stl and step. But Aurora apparently doesn't want to read them.

The only timea Aurora has managed to read a file created by Rhino, this was the result (.stl file):

On the left side is what it looks like in Rhino, on the right side is what it looks like in Aurora.

Can you please tell me what am I doing wrong and what is the best way to import geometries from Rhino (or other 3D modelling software) to Aurora?
Thanks.

[Daiquiri]

Update:

I have managed to do the import of the .stp file!
Here is where the problem was: the paths for converters were not correctly defined.

I would suggest to all the Aurora users who are having difficulty with importing 3D geometries to check if the "Options" ---> "Paths" effectively point to the folders where .exe converter files are placed.

For example, by default the Geocon path stops at "\z88aurorav1\addons\geocon\" but this is wrong, because the folder "geocon" contains another folder ("win32" in my case - XP user) where the converter is installed. So it is ncecessary to click on "other" and choose this additional "win32" path.
The same operation has to be done for all 3 converter paths.

However, the .stl imported file still looks like in the picture above...

Slavi

[Z81]

Dear daiquiri,

on our homepage you can find an installation manual, describing the installation procedure including the
respective paths, everyone has to chose. These pathes are derived from the fact that we wanted to leave the
choice to the user, where to install our software and which pdf-reader, browser or media-player she or he prefers.

Concerning your questions on the exchange formats:
Normally the STEP-interface (.stp) works best for exchanging CAD-data (application protocol AP 203 or
214; export geometry as a volume).
If you want to use the STL-interface, be sure to export an ASCII-STL (see Z88Aurora exchange dialog window)
not a binary one. But the file's quality depends on the respective CAD-software you use; we have no
influence on possible export errors, such as wrong oriented triangles in the STL's surface mesh.
If you get an error during meshing the part, please see netgen.log resp. tetgen.log in your Z88Aurora working
directory. If you find a message like

Code: Alles auswählen

 ERROR: TRIG 30135 has 5 neighbours!!!!

or

Code: Alles auswählen

Error:  Invalid PLC! A point and a segment intersect.

you know (now) the file export of the CAD-software wasn't quite correct.

I remodeled your example files in Pro/ENGINEER and imported them into Z88 Aurora as STEP (export as
volume) and as STL-file (ASCII-format). Both were flawlessly meshed by tetgen as well as netgen
(see picture below).

I would propose to contact RHINO software to get detailed descriptions on their export options.
Normally there are parameters like "chord height" or "aspect ratio", which can positively influence the
export file's quality.

If you have any further questions, don't hesitate to ask.

Good luck and best regards,
Z81

PS: In case you want some more information on Z88Aurora, fortunately we included several quite detailed
manuals. Just click on "Help" in the menubar and open the theory manual (FEA basics), the user manual
(how to operate our program) or you look at the example files (you can find the ready-to-run project folders
in your installation folder subdirectory "docu\bsp\1" tp "13"; especially on your questions concerning STL-files
see example no. 3 "piston rod")
questions:

[Daiquiri]

Thank you very much for the reply, much appreciated.

"Error: Invalid PLC! A point and a subface intersect" - this is the error message I am encountering. So you're saying that it could be Rhino's error? So strange - Rhino has become one of industry standards when it comes to 3D modelling, I would expect it to perform better than that. But I will for sure check that possibility.

I will also give a look at the manuals and example files you have indicated.

Thanks again.

Slavi

[auroraIco]

I ´ve used Rhino for modelling a 3D geometry for Z88Aurora serveral times without any problem. But Z81 is right, while exporting stl´s in Rhino you have some options for a better stl quality. I strongly recommend you to use this features, then you won´t have any problems with the import.

Greetings,
aurora_ico

[Daiquiri]

Thanks for the reply.

Your post has made me think about the process of exporting the mesh from Rhino, so I have checked out the exported geometry more closely and have found out where the problem is.
Basically, the cylinder tube and the rectangle base in the picture are two separate objects, and have been exported by Rhino as two unconnected meshes.

So what did I do then:
- I have joined the two bodies to create one object
- I have exported the .stl file of the new object
- imported the .stl into Aurora. The stl mesh is now ok, with no discontinuities.
- meshed with tetragen - it works.
- deleted the mesh and meshed with netgen - it works.

So it looks ok now, the case can be closed.
Thank you very much again (noth of you guys/girls) for the help.

All the best,

Slavi

[Z81]

Dear Slavi,

we're glad we could help.

Good luck with Z88Aurora and best regards,
Z81