2010/6/24 Thiago Franco Moraes <totonixs...@gmail.com> > On Thu, Jun 24, 2010 at 10:27 AM, Thomas Paviot <tpav...@gmail.com> wrote: > > Hi Thiago, > > I also noticed a strong memory consumption and cpu usage with big STL > files > > (1e6 faces is actually a *huge* number of faces). > > The thing is : why do you want to load these STL files? If it is only for > > visualization, may be OCC/pythonOCC is not the best tool for that need > (you > > talk about MeshLab, which I don't know). > > Now, if you want to do 3D modeling over your STL file (like add a chamfer > on > > an edge, drill a hole, slice the shape for manufacturing etc.) then you > > *need* a 3D modeling library and pythonOCC can help you. But, in that > case, > > the STL file needs to be mapped to the OCC internal data model > > (TopoDS_Shapes, *Edges, Vertices*) and that's why the loading requires so > > much memory/cpu usage. So I don't know if you face a bug : OCC should be > > compared to another modeling tool, and that's a benchmark I didn't make. > > Best Regards, > > Thomas > > Hi Thomas, > > I'm developing a open source medical software named InVesalius [1], > from medical exams (CT, RMI) it generates STL to be used in 3D > printers to print phisical models that doctors and odontologists can > use to plan a surgery. Our software is developed using VTK [2]. Now > our objective is to convert that STLs to STEP to use in CAD softwares. > > Thanks! > > [1] - http://svn.softwarepublico.gov.br/trac/invesalius > [2] - http://www.vtk.org/
Conversion from CAD to STL, then STL to STEP and back to CAD is a strange workflow. The STEP file generated from the STL mesh will be huge and any CAD program will fail loading it (well, that's an assumption, didn't test). Furthermore, the conversion from a mesh to a BRep geometry is still an open issue. According to me, a better way is to generate the STEP and STL files from the same CAD program. VTK does not handle STEP files and, in a sense, it can be easily understood : the "V" of VTK stands for "Visualization", whereas STEP is rather related to modeling. I think that both OCC and VTK should be used in a complete modeling/visualization application. The salome development team (http://www.salome-platform.org) recently commited a code named 'OCC2VTK'. It's not released yet, but it could be very interesting to have both libraries interoperable. Best Regards, Thomas > > > 2010/6/24 Thiago Franco Moraes <totonixs...@gmail.com> > >> > >> Hi all, > >> > >> I've been trying to read STL files. With small STL files it reads > >> normally. With not so big STL files (like the one I've just tried to > >> read that have 51 MB, binary, 534678 vertices, 1069782 faces) it can't > >> read, the CPU usage is about 100% and memory grows up from a few MB to > >> 4 GB then I have to kill my script. Using Meshlab the memory usage is > >> about 270 MB. I've tried to use STLImporter class and StlAPI class. > >> Bellow the code I used: > >> > >> from OCC.Utils.DataExchange import STL > >> reader = STL.STLImporter('file.stl') > >> reader.ReadFile() > >> > >> Ah, I'm using the packages from Ubuntu 10.04 64 bits, the last version > >> in PPA repository [1]. > >> > >> I have done something wrong on trying to read that file? Is it a bug? > >> If necessary I can upload the STL in some place. > >> > >> Thanks! > >> > >> [1] - https://launchpad.net/~cae-team/+archive/ppa > >> > >> _______________________________________________ > >> Pythonocc-users mailing list > >> Pythonocc-users@gna.org > >> https://mail.gna.org/listinfo/pythonocc-users > > > > > > _______________________________________________ > > Pythonocc-users mailing list > > Pythonocc-users@gna.org > > https://mail.gna.org/listinfo/pythonocc-users > > > > > > _______________________________________________ > Pythonocc-users mailing list > Pythonocc-users@gna.org > https://mail.gna.org/listinfo/pythonocc-users >
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