Hello all,

does anyone have experience with the Salome Open-Cascade project? It looks quite interesting at first sight. I tried running it but did not suceed due to my Linux version I think.

Mattijs

Hi Mattijs.
Did you get it working?
I installed it a while back on my Debian system, but had some problems initially. I had to symlink some libraries to suit Open Cascade as I recall, but I don't remember the specifics. What kind of error messages do you get?

Hi Rasmus,

no never did. Didn't spend too much time on it though.

I have installed Opencasde on winXP: it works.
OpenCascade is usefull only if you want to develop your own cad: it is a set of libraries.
On Linux I have installed Salome: it seems to me this software requires a great amount of hardware resources and I have not been able to do anything esle than installing the software.
There is an interesting way to use OCC by Python programmers: make a search with the key word pythoncascade.
I would like to know if someone is able to use OCC with java: is there any wrap or is it necessary to use jni ?

Giuseppe

[gschaider]

Has anyone here been able to start SALOME?

And the other question: does anyone know how "alive" that project is? I did find only one date on the website(http://www.salome-platform.org/): that some stuff was delivered to CEA/DEN in the Dec 2003.

[kortelainen]

Hi Giuseppe!

I have managed to install OpenCASCADE and SALOME on my Linux machine and even get SALOME to start. But I haven't been able to do anything useful with it. I didn't waist too much time with it.

There is another open source meshing tool project going on that uses OCC, jCAE (http://jcae.sourceforge.net/). This tool is built on Netbeans platform and uses OCC through java (as far as I understand these things). It looks very promising, but unfortunately it isn't able to produce any volume mesh yet. But anyway, the software is relatively easy to install (after you have installed OpenCASCADE) and it might be a good starting point for further development.

- Juha -

[billy]

Hi Juha,

I tried to install OpenCASCADE and SALOME but I can't get SALOME to start. What linux system do you have?

Billy.

[kortelainen]

I'm using Fedora Core 2. I used precompiled version of SALOME. I had some difficulties with SALOME until I noticed I was using a wrong python interpreter (needed to unset a python environment variable). Tell me if you get SALOME to work and manage to create a real volume mesh.

- Juha -

[billy]

Hi,

I am using linux Suse 9.2 and I can't get it work. There is some problem with Java and/or environment variables. I will try again next week.

[morne]

Hi,

I initially tried installing Salome on vector linux 5.0 (slackware based), since it seemed promising, no luck with that though. It's apparently pre-configured (using xml files) for RedHat 8&9 so I installed RedHat 9 and got it working no problem (eventually got rid of RH9 after playing around with it). The cad/import interface is pretty good. can import igs, step, brep files and stl as well I think. The mesh generation interface is a bit clumsy though. Kinda frustrating since it has a netgen plugin but doesn't automatically generate a tet mesh as you would in netgen. You have to define 1D,2D, and 3D algorithims and Hypotheses (salome terminology) anyway, it gets complicated. The other problem is that it only exports a mesh in MED or UNV format and I've never even come across these formats. After meshing there is a "supervisor" module which is supposed to provide the ability to link your case to a solver (I think). I got so frustrated with the meshing utility I kinda gave up at this point so I never actually got a case to run/compute. One last point there is a serious lack of documentation and support. The salome forum has probably 10 postings in total. Maybe after a few more users (with more skill and patience than me) get to playing around with it and discussing it, it'll become more useable.

I think the idea of a core software platform for multi-physics simulation is great but salome has some growing up to do before it reaches its full potential.

well that's my 2cents

Cheers,
M

[billy]

Hi,

Maybe the UNV format is i-deas universal file.

[mattijs]

Hi Morne,

sounds like a pretty impressive tool. Does the cad engine do surface-surface intersection and generate say an stl file?

Is its only mesh generation capability netgen? Or does it have its own mesh generator?

Tet only? There was some meshing project on the OpenCascade site some time ago but I never saw that active.

Can you convert the unv format with the ideasToFoam converter? If not should be easy enough to take an existing converter and make it read it.

[morne]

Hi Mattijs,

The cad engine's capabilities are pretty comprehensive in terms of functionality but again kinda clumsy in terms of usability. Maybe I'm a bit spoiled because I'm used to Solid Edge. I'm pretty sure I remember seeing a surface intersection tool, but don't quote me on that. Basically I didn't play around with the cad engine too much just used it to import igs and step files generated by Solid Edge.

NetGen is one of it's meshing algorithms but it's not the only one. (I was hoping it would be a simple automatic process so I checked it out first). You can generate tets or hexes, but the method is kind of a semi-automatic process. For example say I wanted to mesh a cylinder with a hole through it(simple enough). I can consider a rectangular section rotated about its centre axis. so I discretetise the edges as 1-D meshes based on certain conditions (av. length or start-length end-length) Then I define a 2-D mesh again with conditions, quad elements with av. area=100(mm^2). You can continue with this "manual" method for all the faces then tie it all together with a 3-d Algorithm (hex mesh with max vol=...), or you can revolve the mesh and generate the 3-D elements that way. Like I said I found it to be rather clumsy but maybe I wasn't following the best procedures. Unfortunately there isn't a nice tutorial to follow and the help files weren't too enlightening.
If anyone wants to check it out the link is
http://www.salome-platform.org/download
You have to register(free) to download the files.
I haven't tried to convert the Unv file so if you do get a handle on it let me know.

Cheers

[mattijs]

Hi Morne,

thanks for the info. That cad import went without problems? Can you triangulate the individual bits and output them as e.g. stl? (so even without intersection)

Is it hard to get to run on anything but Redhat?

[billy]

Has anybody tried FreeCAD?

http://free-cad.sourceforge.net/

[morne]

Hi Mattjis,

sorry for the delayed reply. haven't been watching the posts lately.

As far as I remember the only export options were UNV(Ideas universal?) and MED(its native format).

I found it difficult to get it running on anything other than redhat, but that's not saying much because I'm still kind of a Linux Newbie. If you're comfortable editing xml files I think you can manually configure the installation, otherwise it has xml files pre-written/pre-configured for redhat 8&9.

If anyone else has tried it I'm really interested to know if someone has managed to generate hex meshes effectively.

Cheers
M

[kortelainen]

Hi, Morne, Mattijs and others,

Just installed the SALOME 2.2.2 the other night and got it working on my Fedora Core 4. I have to say that Morne's right, SALOME is still very clumsy to use. After playing with it for some time I was able to create a hexa mesh inside a simple extruded geometry using some 'average volume hyphotesis' or something, but I didn't figure it out how to control the size distribution of the mesh. I think to be able to cotrol the element sizes, the mesh must be constructed from edges and faces. The export was in UNV, MED and some plain text format which created a .dat file (looked quite similar to the EnSight post-processor mesh format). There might be potential in this software but still a lot to do to make it user friendly.

- Juha -

[kortelainen]

Hi, again

My previous posting above was a bit inaccurate, I'm sorry. I checked the structured mesh creation procedure I had used in SALOME once again, and it was:
Create hyphoteses:
- 'Average length'
- 'Propagation of 1D Hyp. on opposite edges'
Create Algorithms:
- 'Wire discretisation'
- 'Quadrange (Mapping)'
- 'Hexahedron (i,j,k)'
Collect all this into the Global Hyphotesis and compute the mesh. Works atleast on a simple geometry. It looks like SALOME is using native files in hdf format, so the FOAM input could be generated from there, too.

- Juha -

[mattijs]

Hi Juha,

Did you download the binary pack of Salome? Was it working straight out of the box?

Last time I tried installing open-cascade the installation gui wouldn't even run.

[kortelainen]

Hello Mattijs,

I installed the SALOME complete version (CD's image). It includes everything you need to run SALOME, also OpenCASCADE. There seems to be something broken in the separate OpenCASCADE 5.2 package, but that's another story.