diff -r 232e7634cc8a -r b27b90fb993f src/polygoncache.cpp
--- a/src/polygoncache.cpp	Thu Jun 09 13:32:55 2022 +0300
+++ b/src/polygoncache.cpp	Thu Jun 09 19:11:27 2022 +0300
@@ -11,12 +11,23 @@
 	PolygonElement element,
 	const glm::mat4& transform)
 {
-	visitPoints(element, [&transform](glm::vec3& p) {
+	visitPoints([&transform](glm::vec3& p) {
 		p = transform * glm::vec4{p, 1};
-	});
+	}, element);
 	return element;
 }
 
+PolygonCache* findPolygonCacheForModel(Model* model, DocumentManager* context)
+{
+	std::optional<ModelId> modelId = context->findIdForModel(model);
+	if (modelId.has_value()) {
+		return context->getPolygonCacheForModel(modelId.value());
+	}
+	else {
+		return nullptr;
+	}
+}
+
 static std::vector<WithId<PolygonElement>> getPolygonsAt(
 	const Model* model,
 	GetPolygonsContext* context)
@@ -39,24 +50,20 @@
 			[&](const Colored<ConditionalEdge>& cedge) {
 				result.push_back({{cedge, cedge.color}, id});
 			},
-			[&](const Colored<SubfileReference>& ref) {
+			[&result, &id, context](const Colored<SubfileReference>& ref) {
 				Model* dependency = context->documents->findDependencyByName(context->modelId, ref.name);
 				PolygonCache* cache = nullptr;
-				if (dependency != nullptr)
-				{
-					const auto dependencyModelId = context->documents->findIdForModel(dependency);
-					if (dependencyModelId.has_value()) {
-						cache = context->documents->getPolygonCacheForModel(dependencyModelId.value());
-					}
+				if (dependency != nullptr) {
+					cache = findPolygonCacheForModel(dependency, context->documents);
 				}
 				if (cache != nullptr) {
 					const bool needInverting = glm::determinant(ref.transformation) < 0;
-					const auto& modelPolygons = getCachedPolygons(
+					const PolygonCache::vector_type* modelPolygons = getCachedPolygons(
 						cache,
 						dependency,
 						context->documents);
-					result.reserve(result.size() + modelPolygons.size());
-					for (WithId<PolygonElement> polygon : modelPolygons) {
+					reserveMore(result, modelPolygons->size());
+					for (WithId<PolygonElement> polygon : *modelPolygons) {
 						polygon = {transformed(polygon, ref.transformation), polygon.id};
 						if (needInverting != ref.inverted) {
 							gl::invert(polygon);
@@ -81,7 +88,7 @@
  * @param documents Documents to use to resolve subfile references
  * @return vector of GL polygons
  */
-const std::vector<WithId<PolygonElement>> &getCachedPolygons(
+const PolygonCache::vector_type* getCachedPolygons(
 	PolygonCache *cache,
 	Model *model,
 	DocumentManager *documents)
@@ -97,5 +104,5 @@
 		}
 		cache->needRecache = false;
 	}
-	return cache->cachedPolygons;
+	return &cache->cachedPolygons;
 }