According to the help files it *IS* implemented in Impress:

From help -  3D rotation object; converting to:

Convert to 3D Rotation Object

Converts an object into a three dimensional rotation object.
To access this function...
Choose Modify - Convert - To 3D Rotation Object (OpenOffice.org Draw only)
Open context menu of selected object - choose Convert - To 3D Rotation Body
(OpenOffice.org Draw and OpenOffice.org Impress)

The selection will be converted to a contour.
This will also take line geometry into account. For example a contour
will be converted into a three-dimensional object.


Works OK in Draw AND in Impress.

Natalie