Format IDTF U3D PDF
In newer Acrobat plug-in releases, you must check the 'Enable 3D content' item in the '3D Preferences' panel (right mouse menu on render area) before the 'uncluttered' mode works. This also removes the nagging display permission dialog.
The built-in PDF renderer of the Chrome browser does not yet support the display of 3D content.
On Firefox, a structure rendering may sometimes not show up before you click onto the drawing area.
For best display quality, especially with space-filled models, enable "Double-sided rendering" in the '3D Preferences' panel