******************* This email originates from outside Imperial. Do not click on links and attachments unless you recognise the sender. If you trust the sender, add them to your safe senders list https://spam.ic.ac.uk/SpamConsole/Senders.aspx to disable email stamping for this address. ******************* Dear all, I have just started studying Nektar++ for the purpose of adding a new type of element for my research. It is my pleasure to join this great user group. As a first step, I'm exploring the function for reading my mesh in Swansea .plt format, which is virtual void Nektar::NekMesh::InputSwan::Process() within file library/NekMesh/Module/InputModules/InputSwan.cpp. Some improvements have been made to the function so it successfully converts a linear .plt mesh in Swansea format to a Nektar++ .xml session file with boundary faces on each surface fall into an individual COMPOSITE. However, the function seems able to read the 3rd order tetrahedral mesh (at least for the connectivity), but the boundary faces are just linear triangles. Would the subsequent processing convert the linear faces into curved ones? In fact, the NekMesh main function will crash after a successful return from InputSwan::Process(): [InputSwan] Reading Swansea mesh file 'm6.plt' [InputSwan] # tetrahedra : 235377 [InputSwan] # points : 1079083 [InputSwan] mesh order : 3 [InputSwan] ND : 20 [InputSwan] Mesh statistics: [InputSwan] - Mesh dimension : 3 [InputSwan] - Element dimension : 3 [InputSwan] - Has CAD attached : no [InputSwan] - Node count : 41093 [InputSwan] - Edge count : 281235 [InputSwan] - Face count : 475520 [InputSwan] - Elements : 235377 [InputSwan] - Bnd elements : 9532 [InputSwan] - Number of composites : 19 [InputSwan] - Lower mesh extent : -125 0 -125 [InputSwan] - Upper mesh extent : 125 124.901 125 [InputSwan] Element counts (regular/deformed/total): [InputSwan] - Triangle : 0 9532 9532 [InputSwan] - Tetrahedron : 0 235377 235377 [InputSwan] Finished reading mesh. [InputSwan] - Element dimension : 3 [InputSwan] - Space dimension : 3 [InputSwan] - No. of nodes : 41093 [InputSwan] - No. of 3D elements : 235377 [InputSwan] - No. of boundary elements : 9532 [InputSwan] - Elapsed time: 156.314s. [OutputNekpp] Writing Nektar++ file 'm6.xml' Fatal : Level 0 assertion violation Where : /lustre/xi.zou/Documents/work_folder/nektar/nektar-v5.2.0/library/NekMesh/MeshElements/Face.cpp[79] Message : Face nodes of tensor product only supported for quadrilaterals. terminate called after throwing an instance of 'Nektar::ErrorUtil::NekError' what(): Level 0 assertion violation Where : /lustre/xi.zou/Documents/work_folder/nektar/nektar-v5.2.0/library/NekMesh/MeshElements/Face.cpp[79] Message : Face nodes of tensor product only supported for quadrilaterals. I look forward to hearing from the experts on NekMesh and a further discussion. Best regards, Xi Dr. Xi Zou xi.zou@swansea.ac.uk<mailto:xi.zou@swansea.ac.uk> Research Assistant Zienkiewicz Institute for Modelling, Data and AI Faculty of Science and Engineering Swansea University Swansea, UK