Using paraview to present the shape of fracture surface

Hello,

I am using JCFpm material for simulation of triaxial compression.I want to study the shape of the fracture surface of the sample (perhaps by connecting the fracture of the bonding bond?).
I have tried Law2_ScGeom_JCFpmPhys_JointedCohesiveFrictionalPM(recordCracks=True) and VTKRecorder(iterPeriod=500,initRun=True,fileName='triax/JFFPM-',recorders=['spheres','jcfpm','cracks'],label='vtk') to record crack information,then I get the cracks.vtu files.However,when I open the files in paraview,what I get seems to be a separate message about the sphere.What should I do to connect them into a continuous plane that is easy to study.

Thanks for help!