This snippet exemplifies how to export a 3D array into ParaView without the need of writing a VTK file. This is a classical approach to export large volumes of data preferred in highly performing computational (HPC) scenarios. ( like reading/writing [10,000]^3 arrays )
This example outputs 3 files: the geometry.h5, the field.h5, and the solution.xmf. The 3 files are required to be in the same folder. But for opening the array in ParaView/Visit, only the *.xmf file is initially required. ParaView/VisIt will then load the two h5-files.
More details are found inside the script. Happy coding! ;D