Hi Ken, Thanks for the elaborate explanation. I'll think of something.
Sven ----- Original Message ----- From: "Moreland, Kenneth" <kmo...@sandia.gov> To: "Sven Buijssen" <sven.buijs...@tu-dortmund.de>, "paraview@paraview.org" <paraview@paraview.org> Sent: 11/11/09 15:48:59 Subject: [Paraview] Rendering bug? > I do not think that this is a rendering problem. I think you have just > fooled the filter that extracts the external faces of the blocks (which > is what is actually rendered). Notice that when you arrange the > overlapping meshes exactly as you are doing, that some of the faces are > coincident. In particular, the face that is missing is coincident. Up > to the point before you run clean to grid, these faces are topologically > distinct because they use an independent (although coincident) set of > points. When you run clean to grid, these coincident points are merged. > When the points are merged, the cells from the two meshes now share the > same indexed points. At this point, these faces are no longer > topologically distinct. The external faces filter notices that these > two faces use the same points and marks it as a neighbor face (this is > the definition of a neighbor face) and “correctly” removes it. > > The problem is basically that when you append the data sets you are > creating a non-manifold mesh. To correct the problem, you need some > sort of filter that identifies coincident cells and removes duplicates. > I know of no such filter, so you will probably have to write your own. > > -Ken > > > On 11/11/09 7:33 AM, "Sven Buijssen" <sven.buijs...@tu-dortmund.de> wrote: > > Hi, > > I've come across something that I consider a rendering bug, but > before filing a > bug report I'd like to discuss it first. Maybe it sounds familiar. > (I'm guess > it's not related to the z-fighting issue discussed last week.) > > I have two volume grids consisting of hexaeder which partially > overlap (wavelet > sources for demonstration purposes in the attached *.pvsm file). > After applying > AppendDataSets and CleantoGrid filter it looks like the resulting > grid contains > all points and cells except the cell at the intersection of the two > grids. See > attached image. > But the "missing" cell is actually there. Twice. It can be confirmed > by applying > a ProgrammableFilter to add a cell array with cell numbers and > applying a > Threshold filter. Set both lower and upper threshold to either 0 or > 30 to verify > that the "missing" cell is still there. It simply not rendered any more. > > It happens with PV 3.6.1 binary release and PV compiled from CVS > HEAD. (The > state file has been created with PV from CVS HEAD.) > > Any thoughts? > > Thanks > Sven > > > > **** Kenneth Moreland > *** Sandia National Laboratories > *********** > *** *** *** email: kmo...@sandia.gov > ** *** ** phone: (505) 844-8919 > *** web: http://www.cs.unm.edu/~kmorel > _______________________________________________ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the ParaView Wiki at: http://paraview.org/Wiki/ParaView Follow this link to subscribe/unsubscribe: http://www.paraview.org/mailman/listinfo/paraview