#923

src/ifcconvert/IfcConvert.cpp

@@ -349,11 +349,13 @@ int main(int argc, char** argv) {
 		    "Specifies the cut section height for SVG 2D geometry.")
 		("section-height-from-storeys", "Derives section height from storey elevation. Use --section-height to override default offset of 1")
 		("use-element-names",
-            "Use entity names instead of unique IDs for naming elements upon serialization. "
+            "Use entity instance IfcRoot.Name instead of unique IDs for naming elements upon serialization. "
             "Applicable for OBJ, DAE, and SVG output.")
         ("use-element-guids",
-            "Use entity GUIDs instead of unique IDs for naming elements upon serialization. "
+            "Use entity instance IfcRoot.GlobalId instead of unique IDs for naming elements upon serialization. "
             "Applicable for OBJ, DAE, and SVG output.")
+		("use-element-numeric-ids", "Use the numeric step identifier (entity instance name) for naming elements upon serialization. "
+			"Applicable for OBJ, DAE, and SVG output.")
         ("use-material-names",
             "Use material names instead of unique IDs for naming materials upon serialization. "
             "Applicable for OBJ and DAE output.")
@@ -426,6 +428,7 @@ int main(int argc, char** argv) {
 	const bool layerset_first = vmap.count("layerset-first") != 0;
 	const bool use_element_names = vmap.count("use-element-names") != 0;
 	const bool use_element_guids = vmap.count("use-element-guids") != 0;
+	const bool use_element_stepids = vmap.count("use-element-numeric-ids") != 0;
 	const bool use_material_names = vmap.count("use-material-names") != 0;
 	const bool use_element_types = vmap.count("use-element-types") != 0;
 	const bool use_element_hierarchy = vmap.count("use-element-hierarchy") != 0;
@@ -681,7 +684,8 @@ int main(int argc, char** argv) {
 
     settings.set(SerializerSettings::USE_ELEMENT_NAMES, use_element_names);
     settings.set(SerializerSettings::USE_ELEMENT_GUIDS, use_element_guids);
-    settings.set(SerializerSettings::USE_MATERIAL_NAMES, use_material_names);
+	settings.set(SerializerSettings::USE_ELEMENT_STEPIDS, use_element_stepids);
+	settings.set(SerializerSettings::USE_MATERIAL_NAMES, use_material_names);
 	settings.set(SerializerSettings::USE_ELEMENT_TYPES, use_element_types);
 	settings.set(SerializerSettings::USE_ELEMENT_HIERARCHY, use_element_hierarchy);
     settings.set_deflection_tolerance(deflection_tolerance);

src/serializers/GeometrySerializer.h

@@ -50,8 +50,11 @@ public:
 		/// Order the elements using their IfcBuildingStorey parent
 		/// Applicable for DAE output
 		USE_ELEMENT_HIERARCHY = 1 << (IfcGeom::IteratorSettings::NUM_SETTINGS + 5),
-        /// Number of different setting flags.
+        /// Use step ids for naming elements.
-        NUM_SETTINGS = 5
+		/// Applicable for OBJ, DAE, and SVG output.
+		USE_ELEMENT_STEPIDS = 1 << (IfcGeom::IteratorSettings::NUM_SETTINGS + 6),
+		/// Number of different setting flags.
+        NUM_SETTINGS = 6
     };
 
     SerializerSettings()
@@ -82,7 +85,8 @@ public:
     {
         if (settings_.get(SerializerSettings::USE_ELEMENT_GUIDS)) return o->guid();
         if (settings_.get(SerializerSettings::USE_ELEMENT_NAMES)) return o->name();
-        return o->unique_id();
+		if (settings_.get(SerializerSettings::USE_ELEMENT_STEPIDS)) return "id-" + boost::lexical_cast<std::string>(o->id());
+		return o->unique_id();
     }
 
 protected:

src/serializers/SvgSerializer.cpp

@@ -806,6 +806,8 @@ std::string SvgSerializer::idElement(const IfcUtil::IfcBaseEntity* elem) {
 			? static_cast<std::string>(*elem->get("GlobalId"))
 			: ((settings().get(SerializerSettings::USE_ELEMENT_NAMES) && !elem->get("Name")->isNull()))
 			? static_cast<std::string>(*elem->get("Name"))
+			: (settings().get(SerializerSettings::USE_ELEMENT_STEPIDS))
+			? ("id-" + boost::lexical_cast<std::string>(elem->data().id()))
 			: IfcParse::IfcGlobalId(*elem->get("GlobalId")).formatted());
 	return type + "-" + name;
 }