def execute(self, context):
        """Export selected cameras as :code:`Instant-NGP` JSON file."""
        assert len(self.files) == 1
        ofp = os.path.join(self.directory, self.files[0].name)

        cameras, _ = self.get_selected_cameras_and_vertices_of_meshes(odp="")
        for cam in cameras:
            assert cam.get_calibration_mat() is not None

        InstantNGPFileHandler.write_instant_ngp_file(ofp, cameras, op=self)

        return {"FINISHED"}
Export selected cameras as :code:`Instant-NGP` JSON file.
photogrammetry_importer/operators/instant_ngp_export_op.py