Function Syntax: ConvertMultiplePolylines Version: 1.0 Date: 20.06.2026 6:38:58PM AI Description 🧩 ConvertMultiplePolylines is an AutoCAD AutoLISP utility for converting and optionally joining LINE old 2D POLYLINE and LWPOLYLINE geometry. 📌 The program combines legacy 2D POLYLINE conversion with PEDIT joining in one configurable workflow. 🎛️ An embedded DCL dialog lets the user process selected entities or all compatible entities in the drawing and define the joining fuzz distance. Function Syntax 🚀 Main command: ConvertMultiplePolylines 🎛️ Processing mode: Select entities or All entities in drawing 📏 Default joining fuzz distance: 0.01 🔗 Set the fuzz distance to 0 for conversion only with no joining. SEO Optimized Overview 📐 Supported source objects are LINE LWPOLYLINE and valid old style 2D POLYLINE entities. 🔄 Old 2D POLYLINE objects are rebuilt as modern LWPOLYLINE entities before the final PEDIT operation. 🧬 The legacy conversion preserves supported vertex coordinates widths bulges elevation closed state pline generation state and important entity properties. 🔗 When the fuzz distance is greater than 0 the routine uses PEDIT Multiple Join with Extend jointype. 📌 When the fuzz distance is 0 or less the routine performs the conversion workflow without the Join operation. 🖱️ Selected entities mode first uses the current implied AutoCAD selection when one is available and otherwise prompts for objects. 🌐 All entities mode automatically searches the complete drawing for compatible LINE LWPOLYLINE and old 2D POLYLINE entities. Primary Workflow • Run ConvertMultiplePolylines from the AutoCAD command line. • Choose Select entities or All entities in drawing. • Enter the required Joining fuzz distance. • In selected mode use the implied selection or select LINE LWPOLYLINE and POLYLINE objects. • Valid old style 2D POLYLINE entities are converted to LWPOLYLINE objects. • LINE and LWPOLYLINE objects are added to the working selection set. • The routine runs PEDIT for conversion only or conversion plus joining according to the fuzz value. Functionalities ✅ Embedded DCL interface - provides processing mode and joining fuzz controls. ✅ Selected entities mode - processes only user selected compatible geometry. ✅ Implied selection support - uses already selected AutoCAD objects when available. ✅ All entities mode - automatically gathers compatible objects from the drawing. ✅ Old 2D POLYLINE conversion - rebuilds valid legacy planar polylines as modern LWPOLYLINE objects. ✅ LINE conversion - uses PEDIT Multiple to convert LINE objects into polyline geometry. ✅ Optional polyline joining - joins compatible objects when the fuzz distance is greater than 0. ✅ Adjustable fuzz tolerance - controls the maximum distance accepted by the PEDIT joining operation. ✅ Extend jointype - uses the PEDIT Join Extend option when joining is enabled. ✅ Vertex data preservation - retains coordinates start width end width and bulge data from old 2D polylines. ✅ Entity property preservation - retains supported layer linetype color linetype scale lineweight thickness normal and XData properties. ✅ 3D geometry exclusion - prevents 3D polylines polyface meshes and polygon meshes from entering the legacy conversion. ✅ Session defaults - remembers the last processing mode and fuzz value while the AutoCAD session remains active. Important Commands and Aspects 🧩 OldStyle2LwPolyline rebuilds a valid old 2D POLYLINE as an LWPOLYLINE. 🧩 plm:_is2dpoly rejects 3D polylines polyface meshes and polygon meshes. 🧩 plm:_collect_pset_from_ss prepares the working selection set. 🧩 plm:_run_pedit performs conversion only or conversion plus joining. 🧩 PEDIT is the final AutoCAD conversion and joining engine. Result 🎯 The result is a cleaned and modernized polyline set containing lightweight polyline geometry produced from compatible LINE and old 2D POLYLINE entities. 🔗 When joining is enabled compatible geometry is also joined using the selected fuzz tolerance and Extend jointype. 🧰 This workflow is useful for CAD cleanup legacy drawing conversion boundary preparation quantity takeoff and Civil 3D geometry preparation. Important Notes ⚠️ Only planar old style 2D POLYLINE entities are converted by the legacy conversion routine. ⚠️ 3D polylines polyface meshes and polygon meshes are excluded from legacy conversion. ⚠️ A fuzz value greater than 0 enables joining while a value of 0 performs conversion only. ⚠️ If the entered fuzz value cannot be interpreted as a distance the routine falls back to 0.01. ⚠️ The original old 2D POLYLINE is deleted only after the replacement LWPOLYLINE has been created successfully. SEO Keywords 🏷️ AutoCAD, 🏷️ Civil 3D, 🏷️ AutoLISP, 🏷️ ConvertMultiplePolylines, 🏷️ LWPOLYLINE, 🏷️ 2D POLYLINE, 🏷️ LINE conversion, 🏷️ PEDIT, 🏷️ Polyline join, 🏷️ Fuzz distance, 🏷️ Extend jointype, 🏷️ DCL, 🏷️ Legacy polyline conversion, 🏷️ CAD cleanup, 🏷️ CAD automation, 🏷️ CAD productivity