Attached is a python script which collects AH shape information and stores it into an HDF5 file. It also creates an xml file (xdmf), such that visit can open it without any special reader.
The script itself works for python 2 and 3, and requires h5py to be present.
It will search for all horizon shape files within the current directory, and consider all of them for inclusion. This could be turned into a command line option: feel free.
Currently, the script requires one argument: a valid Cactus HDF5 file, intended to be from the same run and containing all time steps the horizon should be visualized in. The combined AH file(s) will contain the same time steps that are present in the input HDF5 file. If no horizons were found at a certain iteration, a dummy grid will be inserted - such that visit automatically merges time sliders even if horizons are not found at every output iteration.
This script should probably go someplace within the AHFinderDirect thorn, as utility. Please suggest a better name if you don't like the current one.