Using Tetra 4D reviewer to create a 3D PDF from backup data from Creo parametric of an assembly, results in a 3D PDF with components missing. They can be seen in the model tree but are not marked with a +. Formely used AACROBAT V9 PRO EXTENDED which has the same problem, but has an option to import hidden objects which fixed the issue. I cannot see this fix in Tetra 4D?