def connectedVertices(self, index, returnIds=False):
        """Find all vertices connected to an input vertex specified by its index.

        :param bool returnIds: return vertex IDs instead of vertex coordinates.

        .. hint:: |connVtx| |connVtx.py|_
        """
        mesh = self.polydata()

        cellIdList = vtk.vtkIdList()
        mesh.GetPointCells(index, cellIdList)

        idxs = []
        for i in range(cellIdList.GetNumberOfIds()):
            pointIdList = vtk.vtkIdList()
            mesh.GetCellPoints(cellIdList.GetId(i), pointIdList)
            for j in range(pointIdList.GetNumberOfIds()):
                idj = pointIdList.GetId(j)
                if idj == index:
                    continue
                if idj in idxs:
                    continue
                idxs.append(idj)

        if returnIds:
            return idxs
        else:
            trgp = []
            for i in idxs:
                p = [0, 0, 0]
                mesh.GetPoints().GetPoint(i, p)
                trgp.append(p)
            return np.array(trgp)
Find all vertices connected to an input vertex specified by its index.

        :param bool returnIds: return vertex IDs instead of vertex coordinates.

        .. hint:: |connVtx| |connVtx.py|_