That is one way to build a custom application, but not the only way. You can use no ParaView GUI components and still use ParaView as a rendering framework for your application with completely custom GUI components.
I’m not sure what you mean by “core-based”, but you can still use ParaView’s server manager infrastructure to create file readers, filters, views, etc. in a layer built on top of VTK objects. You can invoke VTK classes not wrapped in the server manager layer by providing XML that specifies the wrapping, and you can create custom VTK classes and access them pretty much the same way.
Much thanks to u.
Now I get a deeper understanding of customization in ParaView. I was being puzzled over the complicated hierarchy of ParaView’s API in paraview-docs. Then things goes better when I begin to look into PV’s infrastucture in Visual Studio(project built from source).
Thanks again for ur much detailed help!