topic Associative hatch in ObjectARX Forum

Associative hatch

karl.sch1983 — Mon, 25 Aug 2025 22:44:42 GMT

I have spent all day trying to make an associative hatch and it just doesn't work. It says it is associative in properties panel but doesn't behave as one. I came across this but have not tried it yet. I think it should be possible to make associative hatch without involving reactors. Can anyone point me in the right direction. I am not sure what I am doing wrong. Please help. Note that the boundary is a simple close polyline.

bool AssociativeHatch(const AcDbObjectId& bdryId) { AcDbHatch* pHatch = new AcDbHatch(); pHatch->setDatabaseDefaults(); pHatch->setAssociative(Adesk::kTrue); AcDbObjectIdArray boundaryIds; boundaryIds.append(bdryId); pHatch->appendLoop(AcDbHatch::kExternal, boundaryIds); pHatch->setPattern(AcDbHatch::kPreDefined, _T("_SOLID")); pHatch->evaluateHatch(); AcDbDatabase* pDb = acdbHostApplicationServices()->workingDatabase(); AcDbBlockTable* pBlockTable = NULL; AcDbBlockTableRecord* pMSpaceRecord = NULL; pDb->getSymbolTable(pBlockTable, AcDb::kForRead); pBlockTable->getAt(ACDB_MODEL_SPACE, pMSpaceRecord, AcDb::kForWrite); AcDbObjectId hatchId; pMSpaceRecord->appendAcDbEntity(hatchId, pHatch); pMSpaceRecord->close(); pHatch->close(); return true; }

Re: Associative hatch

daniel_cadext — Wed, 27 Aug 2025 09:24:24 GMT

AcDbHatch doc show to use addPersistentReactor

https://help.autodesk.com/view/OARX/2024/ENU/?guid=OARX-RefGuide-AcDbHatch

static void createHatch(void) { auto ERR = [](Acad::ErrorStatus es) { if (es != Acad::eOk) acutPrintf(_T("Error: %ls"), acadErrorStatusText(es)); }; ads_name ename; ads_point point; if (RTNORM != acedEntSel(_T("\nSelect rec: "), ename, point)) return; AcDbObjectId objId; ERR(acdbGetObjectId(objId, ename)); AcDbObjectIdArray dbObjIds; AcDbEntityPointer pEnt(objId); dbObjIds.append(pEnt->objectId()); AcDbBlockTableRecordPointer pBtr(ACDB_MODEL_SPACE, curDoc()->database(), AcDb::kForWrite); ERR(pBtr.openStatus()); AcDbObjectPointer<AcDbHatch> pHatch; ERR(pHatch.create()); pHatch->setDatabaseDefaults(); ERR(pHatch->setAssociative(Adesk::kTrue)); ERR(pHatch->setPattern(AcDbHatch::kPreDefined, _T("_SOLID"))); ERR(pHatch->setHatchStyle(AcDbHatch::kNormal)); AcDbObjectId hatchId; ERR(pBtr->appendAcDbEntity(hatchId, pHatch)); ERR(pHatch->appendLoop(AcDbHatch::kExternal, dbObjIds)); ERR(pHatch->evaluateHatch()); ERR(pEnt->upgradeOpen()); ERR(pEnt->addPersistentReactor(hatchId)); }

Re: Associative hatch

karl.sch1983 — Fri, 29 Aug 2025 21:01:06 GMT

Thanks Daniel. That worked. I just wasn't sure if there was a different approach available other than the persistent reactor route. Thanks again.