Function Syntax: MleaderStraightTools Version: 1 Date: 29.09.2025 AI+https://forums.autodesk.com/t5/visual-lisp-autolisp-and-general/changing-mleader-aligner-function-to-apply-to-all-mleaders-in/m-p/9062067#M83632 Description 📐 MleaderStraight is an AutoCAD and Civil 3D AutoLISP utility for straightening selected MultiLeader leader lines into clean horizontal or vertical orthogonal segments. 🧭 The tool includes a compact DCL chooser that can process either manually selected MLeader objects or every MultiLeader in the current Model/Paper space layout. Function Syntax 🚀 Main command: MleaderStraightTools 📌 Selection mode: process preselected or interactively selected MULTILEADER objects. 📊 Current-space mode: process all MULTILEADER objects on the active CTAB layout using the 410 layout filter. SEO Optimized Overview 📐 MleaderStraight provides an SEO-friendly AutoCAD MLeader alignment workflow for CAD users who need cleaner annotation geometry, straighter leader lines, and more consistent Civil 3D drafting presentation. 🧩 The routine reads the first leader-line vertices from each MULTILEADER, determines whether the leader is closer to a horizontal or vertical adjustment, and rewrites the leader vertices so the resulting segment is orthogonal. 🖱️ A temporary embedded DCL dialog lets the user choose between interactive selection and all MultiLeaders in the current drawing space. 🗂️ The routine is ModelSpace and PaperSpace aware: it uses the active document space object for temporary construction geometry and uses CTAB to target the correct layout when processing all leaders. Primary Workflow 1️⃣ Load MleaderStraight.lsp in AutoCAD or Civil 3D. 2️⃣ Run the command listed above from the AutoCAD command line. 3️⃣ Follow the prompts or DCL dialog options shown by the routine. 4️⃣ Review the result in the drawing and use AutoCAD Undo if you need to revert the operation. Core Functionalities ✅ Straighten MultiLeader leader geometry for cleaner AutoCAD annotation. ✅ Choose between selected MLeader processing and all MLeaders in the current space. ✅ Supports PICKFIRST preselection via ssget "_I" and manual selection via ssget. ✅ Uses MULTILEADER filters to avoid processing unrelated entity types. ✅ Creates a temporary construction XLINE only for geometric calculation and deletes it immediately after use. ✅ Regenerates all viewports after processing so the updated leader geometry is visible. Important Helper Functions and AutoCAD API Calls 🧩 rh:sammlung_n groups raw vertex coordinate lists into 3D point chunks. 🧩 MleaderStraightTools:get-space-obj returns the active ModelSpace or PaperSpace VLA object. 🧩 MleaderStraightTools:get-all-mleaders-current-space builds a selection set of all MULTILEADER entities on the current CTAB layout. 🧩 MleaderStraightTools:process-ss performs the leader vertex recalculation, temporary XLINE construction, closest-point calculation, vertex update, and viewport regeneration. 🧩 MleaderStraightTools:write-dcl-to-temp writes the embedded DCL definition to a temporary dialog file. 🧩 The local *error* handler unloads the DCL and deletes the temporary DCL file on cancellation or error. Result 📌 Selected MultiLeader objects are updated with cleaner orthogonal leader-line vertices. 📊 The command prints the number of processed MultiLeaders at the command line. 🧹 Temporary DCL files and temporary XLINE objects are removed after processing. Important Notes ⚠️ The routine modifies existing MULTILEADER vertex geometry, so test on a copy of production drawings when validating a new annotation standard. ⚠️ It processes leader line index 0 and is intended for standard MultiLeader objects; complex MLeader configurations with multiple leader branches may need separate review. 🧠 Best selection experience is obtained with PICKFIRST = 1 and PICKADD = 2, as noted in the source comments. Tags 🏷️ AutoCAD, 🏷️ AutoLISP, 🏷️ Civil 3D, 🏷️ MLeader, 🏷️ MultiLeader, 🏷️ Leader Alignment, 🏷️ MLeader Straighten, 🏷️ DCL Dialog, 🏷️ CAD Annotation, 🏷️ Drafting Automation