<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Hi,<div class=""><br class=""></div><div class="">I have attached two files. One is a single-cell complex polyhedron which I wish to be able to use and visualise (as is, without tessellation and tetrahedralization). Using 5.5.0 this fails to slice/cut in paraview in any major plane. Paraview complains about non-manifold (under-connected) edges. To debug I wrote out as a vtkPolyData containing all the faces of this single cell polyhedron. This polyData Slices/cuts just fine. All faces added to the vtp file as VTK_POLYGON, likewise are added as a face-stream when added as a VTK_POLYHEDRON to the vtu file. To be clear, I write the faces out to the vtp in the same loop I build the faces for the single cell vtu mesh, so they are carbon copies of the faces, including numbering, ordering etc. I am aware there are more vertices in the file than need be (27 rather than 19), but it was easier...</div><div class=""><br class=""></div><div class="">My working assumption is that there is no problem visualising and working with cells of this type (non-convex) in paraview (real use cases includes a mesh with many of these types of cells). Clarity on this point would also be good…</div><div class=""><br class=""></div><div class="">I believe paraview should work for concave cells and I suspect it’s a bug (either in paraview or my face-data) because if I use 5.4.1 (or indeed 5.2.0) I can clip the singleCell in the x-plane (with inside-out flag on/off) and I get the expected results. However, in the y and z planes I do not get the expected results and those versions either return an empty result or the whole cell. I get no results in 5.5.0 regardless of plane. Finally, I get no results in 5.5.1 either. So it sort of used to work in earlier versions depending on the plane of slicing, but now does not. </div><div class=""><br class=""></div><div class=""><div class="">I’m not sure what I’m doing wrong, can somebody shed some light or spot an error in the attached file? This may be linked to:</div><div class=""><br class=""></div><div class=""><a href="https://gitlab.kitware.com/paraview/paraview/issues/18003" class="">https://gitlab.kitware.com/paraview/paraview/issues/18003</a></div></div><div class=""><br class=""></div><div class="">Thanks again,</div><div class="">Andy</div><div class=""><br class=""></div><div class=""></div></body></html>