Sets the object snap modes for 3D objects.
Access Methods
Menu:
Tools
Drafting Settings
Shortcut menu: Press Shift while right-clicking in the drawing area and choose 3D Osnap Osnap Settings.
Osnap Settings. Toolbar: Status bar (expanded) 3D Object Snap 
Summary
Displays the 3D Object Snap tab of the Drafting Settings dialog box. You can also set the 3D object snap settings with the 3DOSMODE system variable.
Note: Because 3D object snaps can slow performance, select only the object snaps you need.