Hi Asim, I am not sure if isocontours will work with this filter, but here are a few things that could help you: - You can specify more than one module in the "Modules" parameter, and they will be executed in sequence. - The parameters for each module should also be in "Modules", separated by ":", e.g. isocontour:fieldstr=Q:fieldvalue=1000 - I think the isocontour module only works with .dat and .vtu outputs. Considering this, you could try <FILTER TYPE="FieldConvert"> <PARAM NAME="OutputFile">Q_214_iso2000.vtu</PARAM> <PARAM NAME="OutputFrequency">10</PARAM> <PARAM NAME="Modules"> QCriterion isocontour:fieldvalue=1000:fieldid=4 </PARAM> </FILTER> where you should check the correct fieldid for the Q field (it should be 4 for 3D simulations). Cheers, Douglas ________________________________ From: nektar-users-bounces@imperial.ac.uk <nektar-users-bounces@imperial.ac.uk> on behalf of Asım Önder <asim.onder@gmail.com> Sent: 07 March 2017 07:04:41 To: nektar-users Subject: [Nektar-users] extracting isosurfaces on runtime Dear all, Is there any way to make isocontour module work in filter mode for derived quantities, e.g., Q field? I tried the following in config.xml file for a run using IncNavierStokesSolver solver: <FILTER TYPE="FieldConvert"> <PARAM NAME="OutputFile">Q_214.fld</PARAM> <PARAM NAME="OutputFrequency">10</PARAM> <PARAM NAME="Modules"> QCriterion </PARAM> </FILTER> <FILTER TYPE="FieldConvert"> <PARAM NAME="OutputFile">Q_214_iso2000.fld</PARAM> <PARAM NAME="OutputFrequency">10</PARAM> <PARAM NAME="Modules"> isocontour </PARAM> <PARAM NAME="fieldstr"> Q </PARAM> <PARAM NAME="fieldvalue"> 1000 </PARAM> </FILTER> The first filter works, and writes out the 3D Q field. However, second one does not work as Q is not defined as a field in the solver. Is there any possibility to address this other than extending the related solver to contain the calculation of the field? Thanks, Asim