Function Syntax: Region2Polyline AI+https://forums.autodesk.com/t5/visual-lisp-autolisp-and-general/bypass-user-selection-in-lisp-to-convert-region-to-polyline/m-p/8169231#M101570 Description This AutoLISP routine Region2Polyline converts selected REGION entities into closed lightweight polylines by exploding and rebuilding them with line and arc segments. Written by Gilles Chanteau on 01/01/07. Functionalities: • Command syntax: Region2Polyline. • Prompts the user to select REGION objects in the drawing. • Explodes each REGION into its primitive line and arc components. • Rebuilds the exploded geometry into a closed lightweight polyline. • Handles arc segments by calculating bulge values (arcbulge) to preserve curvature. • Deletes the original REGION objects once converted. • Ensures the new polyline is closed and placed in the correct drawing space (ModelSpace or PaperSpace depending on CVPORT). • Groups the operation into an undo mark for rollback. Key Features: • Converts REGIONS back into editable polylines without loss of arcs. • Works with both ModelSpace and PaperSpace contexts. • Uses robust geometric matching of endpoints to reconstruct polylines. • Preserves geometric accuracy of arcs using calculated bulge factors. Function Syntax • Region2Polyline Typical Workflow • Run Region2Polyline. • Select one or more REGION objects. • The program explodes them, rebuilds the edges as closed lightweight polylines, and deletes the original REGIONs. • The resulting polyline(s) are ready for editing, measuring, or further CAD operations.