I think, for Tetra4DConverter it is not possible to start the 3D Reviewer from within the application.
If we need to alter a 3D-PDF we open the 3D Reviewer and open the respective PDF, make our changes and then Export it to PDF again. I remember that in a former version there was a command “Edit in 3D Reviewer” but in the current version together with Acrobat 2017 it seems to be gone.
Best Regards
Thomas
