Flatten creates a 2D representation of selected objects and projects selected objects on to the current viewing plane, forcing object elevations and thickness to 0.
Select objects: Select objects to convert to 2D
Select objects: Press ENTER
Remove hidden lines? <No>:
You can use FLATTEN to create a 2D drawing from a 3D model or you can use it to force the thickness and elevations of selected objects to 0.
Unlike many traditional methods of 3D to 2D conversion, FLATTEN preserves as much of the drawing's original intelligence as possible. The common practice of plotting to a DXB file and then using DXBIN to re-import, causes the loss of drawing intelligence such as the loss of color and layer information. FLATTEN gets the job done in one step and does not have this problem. Using FLATTEN results in 2D objects that retain their original layers, linetypes, colors and object types where possible.
FLATTEN is similar to a plot of the current view or display. FLATTEN projects selected objects onto the current viewing plane. If your view is not plan when you invoke FLATTEN, the current UCS will be temporarily set to view for the duration of the operation. With respect to UCS=view, the objects that result will be flat.