The 3D Polyline Command

Toolbar	custom
Pull-down	Draw3D Polyline
Keyboard	3DPOLY

The 3D Polyline command works in exactly the same way as the Polyline command. The main difference between a normal polyline and a 3D polyline is that each vertex (pick point) of a 3D polyline can have a different value for Z (height). In normal (2D) polylines, all vertexes must have the same Z value.

3D polyline objects are not as complex as their 2D cousins. For example, they cannot contain arc segments and they cannot be given widths. However, they can be very useful for 3D modeling.

Command Sequence

Command: 3DPOLY
Specify start point of polyline: (pick a point)
Specify endpoint of line or [Undo]: (pick another point)
Specify endpoint of line or [Undo]: (pick a third point)
Specify endpoint of line or [Close/Undo]: (to end, C to close or continue picking points)

Notice that you are not prompted for a Z value each time you pick a point. You must either use one of the Object Snaps to pick a point with the required Z value or use the ".XY" filter to force AutoCAD to prompt for a Z value.