There are many useful functions in VTKExtensions in ParaView. So, it is possible to integrate this package to VTK?
it is possible to integrate this package to VTK?
If by that you mean to build VTK and VTKExtensions together, yes, but only by building ParaView.
If by that you mean to integrate some part of VTKExtensions back into VTK, yes, but that depends of the part and there will be most likely some developpements/testing work needed to integrate it cleanly in the code of VTK.
I means to integrate VTKExtensions into VTK packages, not compile the Paraview to use the VTKExtensions functions.
Possible, needs some C++ skills and VTK knowledge.