The 3D Radial Repeat tool allows you to radially duplicate selected objects in the current view plane by drawing an arc with the mouse. Spiral duplications are also available. The repeat angle is set in the tool's dialog, and the number of duplications is determined by the angle of the arc that you draw. Thus the number of duplications depends on the angle that you indicate-the farther you drag, the more objects are duplicated. In the case of a spiral duplication, you may have any number of complete revolutions.
Spiral staircases are nothing.
The 3D Radial Distribute tool allows you to radially duplicate selected objects in the current view plane by drawing an arc with the mouse. Spiral duplications are also available. This tool is exactly like the 3D Radial Duplicate tool described above, except that the mouse movement is used to indicate the overall arc angle of the duplications. Thus the mouse is used to determine the angle of the last duplication, and all intermediate objects are evenly distributed along this arc. The 3D Tilt tool allows you to distort selected objects so that they will appear to rotate about one of the 3D drawing axes.