[vtkusers] Polydata cell connectivity list

[Wesley Brooks]

David,

Thanks for your help. The program doesn't stall any more it just
doesn't find any cells which share points with each other...

This is the code as it stands now:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    def SupportCheck(self):

        print self.polydata

        self.polydata.BuildLinks(0)

        self.polydata.Update()

        print self.polydata

        for cellid in self.nobad:

            supcell = self.polydata.GetCell(cellid)

            pntid1 = supcell.GetPointId(0)
            pntid2 = supcell.GetPointId(1)

            coord1 = self.polydata.GetPoint(pntid1)
            coord2 = self.polydata.GetPoint(pntid2)

            if coord1[2] == coord2[2]:
                flag1 = self.SelectPoint(coord1[2], pntid1, cellid)
                flag2 = self.SelectPoint(coord2[2], pntid2, cellid)

            if coord1[2] > coord2[2]:
                flag = self.SelectPoint(coord2, pntid2, cellid)

            if coord1[2] < coord2[2]:
                flag = self.SelectPoint(coord1, pntid1, cellid)

        return self.supportlist
                

    def SelectPoint(self, z, pntid, cellid):
        
        cells = vtk.vtkIdList()

        ncells = 0

        self.polydata.GetPointCells(pntid, cells)

        numofcells = cells.GetNumberOfIds()

        for linkedcell in range(numofcells):
            
            idcell = cells.GetId(linkedcell)

            if idcell != self.nobad:

                chkcell = self.polydata.GetCell(idcell)

                chkpntid1 = chkcell.GetPointId(0)

                if chkpntid1 != pntid:
                    flag = self.CheckPnt(chkpntid1, z)
                    
                elif chkpntid1 == pntid:
                    chkpntid2 = chkcell.GetPointId(1)
                    flag = self.CheckPnt(chkpntid2, z)

        if flag == 1:
            if pntid not in self.supportlist:
                self.supportlist.append(pntid)

    def CheckPnt(self, pntid, z):
        
        flag = 1
        
        chkcoord = self.polydata.GetPoint(pntid)

        if chkcoord[2] < z:
            flag = 0

        return flag

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I think my problem is something to do with the BuildLinks(0) call.

Briefly the code is supposed to save the ids of points of cells (each
cell is a line) which are in the list self.nobad and are connected to
no cells which have a point lower than it's lowest point.

However there's not much reason for you to look past the numofcells =
line as this is always seems to equal 1 now which it should not. The
polydata file is fine, I can view it before this opperation.

I've also viewed the polydata before and after the BuildLinks() and
seen no difference between them.

Thanks again for your help.

Wesley.