Hello Chris,
I have imported the surface .vtk objects for the two black holes. When I add meshes for them they appear correctly but are connected, rather than two separate entities. If this doesn't make sense I will attach a picture in a future email.
Is there a way to get rid of this in Visit?
My guess would be that you need to ensure that each of the sets of vtk files for each of the black holes is treated by visit as a separate database.
Could you attach a sample rendering and maybe a screenshot of your VisIt window with the data loaded?
Did you take a look at the visualization tutorial here:
https://docs.einsteintoolkit.org/et-docs/GW150914_VisIt_Tutorial
It shows how to visualize the horizons in the latter part of the tutorial.
Yours, Roland