Add the ability to create countour lines on velocity magnitude
In now time paraview support only creating contour lines on pressure p.
If I want to create the countour line on velocity, which is not allowed by countour, I need to use 'Calculator' field with command "mag(V)", then I've got my Result, and only then I can use this Result in the countour filter to make the lines on my velocity magnitude
AdminUtkarsh Ayachit (Admin, paraview) commented
Try using the "Auto Convert Properties" option available in the Settings dialog (on the General tab). ParaView will auto extract components or compute vector magnitudes when this option is enabled.