PDF is widely accepted as a standard document format and now it supports 3D contents as well. Within the engineering application areas, this new 3D feature may be used to support sharing of 3D documents and thus collaboration between engineering departments, suppliers and partners. In this paper, we describe a system that automatically generates formatted engineering documents including 3D data converted from 3D applications such as commercial 3D CAD viewer. The system consists of two major modules. One is U3D conversion module and the other is PDF conversion module. U3D conversion module extracts geometry, view data, assembly and disassembly information from 3D viewer and converts to U3D format, currently in IDTF text file format. PDF conversion module generates a PDF file and inserts U3D data, various annotation information, and scripts for custom generated operations such as assembly and disassembly in the PDF document.