獲取在 ifcgroup 中分組的元素的 guid

Question

IFCJS 的 API 中是否有 function 以獲取在 ifcgroup 中分組的元素的 guid？ 例如，如果我將一列與一堵牆組合在一起

getElementsFromIfcGroup(guidGroup) ---> return [guidWall, guidColumn]

Answer 1

根據 IFC 架構， IfcGroup實例使用稱為IfcRelAssignsToGroup的間接關系 object 將元素組合在一起。 這意味着您可以像這樣檢索該組中包含的元素：

import { IFCRELASSIGNSTOGROUP as REL } from 'web-ifc';

async function getItemsOfGroup(modelID, groupID) {
  const manager = ifcLoader.ifcManager;
  const relIDs = await manager.getAllItemsOfType(modelID, REL);

  for(relID of groupsIDs) {
    const groupRel = await manager.getItemProperties(modelID, relID);
    if(groupRel.RelatingGroup.value === groupID) {
     return groupRel.RelatedObjects;
    }
  }

  return [];
}

Answer 2

根據安東尼奧的回答，它看起來像這樣：

    async function getItemsOfGroup(modelID, groupID) {
        const manager = viewer.IFC.loader.ifcManager
        // Get all ifcgroups
        const relIDs = await manager.getAllItemsOfType(modelID, IFCRELASSIGNSTOGROUP);
        let relID, relObj, props;
        var guIDs = [];
        for(relID of relIDs) {
            const groupRel = await manager.getItemProperties(modelID, relID);
            // Find the groupID
            if(groupRel.GlobalId.value === groupID) {
                // Search all related objects 
                for(relObj of groupRel.RelatedObjects) {
                    //get object properties 
                    props = await manager.getItemProperties(modelID, relObj.value);
                    //Add guid to array
                    guIDs[guIDs.length] = props.GlobalId.value;
                }
                return guIDs;
            }
        }
        return guIDs;
    }