Bing found the following results
  1. How to Create a 3D PDF from AutoCAD | Spatial - ACIS

  2. AUTOCAD 3D TUTORIAL - By www.EasyEngineering.net.pdf

  3. How to create a 3D PDF from an AutoCAD drawing - YouTube

  4. AutoCAD 3D Made Easy for the Beginning User - Autodesk

  5. How t o Create an AutoCAD 3D PDF - YouTube

  6. How to print 3D objects to 3D PDF from AutoCAD - Autodesk

  7. 3D PDF Tutorial For AutoCAD 2016/17/18 - Autodesk Community