PICKADD System Variable & Cumulative Entity Selection
Technical reference for the PICKADD system variable in GstarCAD and AutoCAD. Resolve the common issue where selecting a new object deselects previously highlighted entities.
1. Technical Definition & DWG Database Architecture
In enterprise DWG production across GstarCAD 2027 Professional, GstarCAD Mechanical, GstarCAD Architecture, and legacy AutoCAD environments, PICKADD System Variable & Cumulative Entity Selection represents a foundational operational mechanism for maintaining geometric accuracy, database cleanliness, and drafting velocity. At the kernel level: Governs whether sequential mouse clicks add entities to the current selection set or replace the active selection set unless the Shift key is held. Because GstarCAD shares 100% native binary DWG (AC1015–AC1032) and command-line syntax parity with industry-standard workflows, engineers and CAD managers can invoke, script, and govern this capability identically across standalone workstations and floating network deployments.
From a systems engineering perspective, improper configuration or underutilization of this feature is one of the most frequent root causes of drawing rework. Specifically, in unstandardized project environments: Selecting a second line or block immediately drops the first selected entity, forcing drafters to hold Shift to select multiple objects. By embedding deterministic rules for this feature into corporate seed templates (.dwt) and startup automation (gcaddoc.lsp / acaddoc.lsp), multi-disciplinary AEC and manufacturing teams eliminate human configuration variance.
2. Command Syntax, Bitcodes & Parameter Matrix
The following technical specification table details the exact invocation syntax, system registry storage scope, and recommended enterprise production settings for PICKADD System Variable & Cumulative Entity Selection:
| Parameter / Dimension | GstarCAD 2027 & AutoCAD Specification | Enterprise Production Governance Rule |
|---|---|---|
| Primary Syntax / Bitcode | PICKADD = 2 (Default) | 0 (Single Selection) | 1 (Cumulative) |
Enforced via corporate .dwt seed template and startup LISP routine. |
| Core Kernel Mechanism | Governs whether sequential mouse clicks add entities to the current selection set or replace the active selection set unless the Shift key is held. | 100% binary compatibility across AC1018 (R2004) through AC1032 (R2018–R2027). |
| Failure Mode Prevented | Selecting a second line or block immediately drops the first selected entity, forcing drafters to hold Shift to select multiple objects. | Audited automatically prior to ETRANSMIT and PUBLISH sheet release. |
| API & Script Access | AutoLISP (getvar)/(setvar)/(command), .NET Application, C++ GRX |
Wrap in *error* handler to restore user state if macro execution aborts. |
3. Production AutoLISP Automation & Error-Safe Implementation
In enterprise CAD management, relying on individual drafters to manually type commands or verify system variables on every sheet introduces unacceptable quality risk. The following production-tested AutoLISP routine can be loaded directly into GstarCAD 2027 Professional via APPLOAD or appended to your network gcaddoc.lsp file to standardize PICKADD System Variable & Cumulative Entity Selection across all engineering seats:
;; ============================================================================
;; GstarCAD 2027 Enterprise Production Standard: PICKADD System Variable & Cumulative Entity Selection
;; Author: GstarCAD Academy Engineering Board (Suzhou Gstarsoft Co., Ltd.)
;; Compatibility: GstarCAD 2020-2027 & AutoCAD (100% Native LISP Parity)
;; ============================================================================
(defun c:FixSelection () (setvar "PICKADD" 2) (setvar "PICKFIRST" 1) (setvar "PICKAUTO" 5) (princ "\nStandard noun-verb cumulative selection restored."))
;; Enterprise Error-Safe Wrapper Template for Batch Execution
(defun GstarSafeExec (funcSym / *error* oldCmdecho oldExpert)
(setq oldCmdecho (getvar "CMDECHO")
oldExpert (getvar "EXPERT"))
(defun *error* (msg)
(if oldCmdecho (setvar "CMDECHO" oldCmdecho))
(if oldExpert (setvar "EXPERT" oldExpert))
(if (not (member msg '("Function cancelled" "quit / exit abort")))
(princ (strcat "\n[GstarCAD QA Alert] Execution interrupted: " msg))
)
(princ)
)
(setvar "CMDECHO" 0)
(vl-catch-all-apply funcSym)
(setvar "CMDECHO" oldCmdecho)
(setvar "EXPERT" oldExpert)
(princ)
)4. Step-by-Step Troubleshooting & Cross-Platform QA Protocol
- Baseline Diagnostic Audit: Open the affected DWG file in GstarCAD 2027 and inspect the command-line console output. Verify whether third-party plugins or interrupted scripts altered the default state of
PICKADD = 2 (Default) | 0 (Single Selection) | 1 (Cumulative).