Similar to Inventor (unfold, unwrap) or to Fusion 360, also AutoCAD can unfold some types of unfoldable 3D objects/surfaces to 2D representation, e.g. for forming sheetmetal or glueing paper, textile or cardboard. The freeware LISP application UnwrapRS by CAD Studio can unfold ruled surfaces, i.e. 3D objects created with the RULESURF command from border curves of any type. Typical examples are: conical surfaces – reducers between ducts of different diameter, transitions (transforms) circle-ellipse or ellipse-rectangle, facade building elements formed by two 3D splines, etc.
The rule surface must be generated in the legacy Polyline mode, i.e. with the MESHTYPE=0 setting. The precision of the surface (and then of its unfold) depends on the setting of the SURFTAB1 variable.
The result of the unfold is a planar representation of the object made of a group of 3D Faces and a group of outline curves around the shape of the unfold (e.g. to be cut from sheetmetal).
You can download the UnfoldRS utility from https://www.cadstudio.cz/freeware, load it into your AutoCAD with APPLOAD and run by typing the UNFOLDRS command. Choose the Polyline mode and select a previously created rulesurf object. See details on https://www.cadforum.cz/cadforum_en/unfoldrs-unfold-3d-surfaces-to-2d-in-autocad-tip12237
Usage of the UnwrapRS utility:
Source: Autodesk
