Re: [vmtk-users] blockstructured hexahedral mesh at bifurcation
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Re: [vmtk-users] blockstructured hexahedral mesh at bifurcation
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From: Luca A. <luc...@gm...> - 2011-04-07 09:55:22
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Dear Regine, The pipe is correct the way you write it. The problem with branch splitting the way you are doing it is that you should place your source seed down at the CCA inlet, not at the bifurcation apex. Don't worry if the centerlines do not meet at the bifurcation "center" (whatever that is), it's correct that way (you can always merge them *after splitting the surface* using vmtkcenterlinemerge). If you want the cut surfaces to match exactly, you have to increase the density of your surface using vmtksurfacesubdivision, using 1 or 2 levels of subdivision. This way the cut will be more "precise" (up to a numeric tolerance). Let me know if this answers your question, best regards Luca On Apr 6, 2011, at 1:50 PM, Ric...@we... wrote: > Dear Luca, > > thank you for your help! Sounds good. I will try my best with pyformex! > > I have two more questions dealing with vmtk branch splitting. I hope you (or somebody else) can help me. > > When I was splitting all three branches of my bifurcation I never managed to start from the same centerline generation. I always had to fix the red dots for the source points newly and therefore the cut surfaces differ a bit, that means the branches don’t really match at the bifurcation. I was using this code: > > “vmtksurfacereader -ifile E:\Regine\ Model_clipped.stl --pipe vmtkcenterlines --pipe vmtkbranchextractor --pipe vmtkbranchclipper -groupids 2 -ofile E:\Regine\Model_branchextract1.stl > vmtksurfaceviewer -ifile E:\Regine \Model_branchextract1.stl -array GroupIds” > > I tried different variations (for the single group ids) to use the same starting point for the branch splitting, but failed. > > The other thing is concerning the position of my branch splitting. It doesn’t look like the one shown at vmtk.org and I am concerned that my mesh won't be good therefore. I tried different positions of the seed point, but it didn't work. I attached two pics showing where I was positioning the seed points and how my branchsplit looks afterwards. > > It would be really nice, if you could help! > > With best regards, > Regine > > > Von: "Luca Antiga" <luc...@gm...> > Gesendet: 05.04.2011 08:53:16 > An: Ric...@we... > Betreff: Re: [vmtk-users] blockstructured hexahedral mesh at bifurcation > > Dear Regine, > if you are interested in a block-structured hexahedral mesh, I strongly suggest you check out pyformex, which does exactly what you look for, http://pyformex.berlios.de/. > You can import an stl file and generate an all-hex mesh. > Hope this helps. > > Luca > > > On Apr 3, 2011, at 10:50 PM, Ric...@we... wrote: > > Dear all, > > I am using the branch splitting to seperate the branches of a vessel bifurcation. My plan is to create a blockstructured hexahedral mesh for such a bifurcation. Since this appeared to be not that easy considering the whole bifurcation (I failed several times), I hoped this would maybe get easier, if I split the branches. Unfortunately I am not that experienced with mesh generation and cfd in general. Does any of you have experience how I can proceed now to get such a blockstructured hexahedral mesh? The only commercial software I have access to are Gambit and TGrid. It would be really nice, if you could help me! > > Thanks a million in advance! > Regine > > > Empfehlen Sie WEB.DE DSL Ihren Freunden und Bekannten und wir > belohnen Sie mit bis zu 50,- Euro! https://freundschaftswerbung.web.de > ------------------------------------------------------------------------------ > Create and publish websites with WebMatrix > Use the most popular FREE web apps or write code yourself; > WebMatrix provides all the features you need to develop and > publish your website. http://p.sf.net/sfu/ms-webmatrix-sf > _______________________________________________ > vmtk-users mailing list > vmt...@li... > https://lists.sourceforge.net/lists/listinfo/vmtk-users > > > > WEB.DE DSL Doppel-Flat ab 19,99 €/mtl.! Jetzt mit > gratis Handy-Flat! http://produkte.web.de/go/DSL_Doppel_Flatrate/2 > <SeedPoints_Centerline.jpg><Branchsplit.jpg> |