When Acrobat X was released, most of the powerful 3D functionality of Acrobat was removed and placed into 3rd party tools.
However, you can still download trial versions of Acrobat 8 and Acrobat 9 that include the enhanced 3D functionality. Links are provided below:
Adobe Acrobat 3D Version 8 (includes Adobe Acrobat 3D Toolkit)
Adobe Acrobat 9 Pro Extended
You may be interested in my previous posts:
Create Adobe 3D PDF directly from Autodesk 3D DWF