Revert "Revert "Check max complexity before bool process""

src/cpp/web-ifc/geometry/IfcGeometryProcessor.cpp

@@ -215,6 +215,10 @@ namespace webifc::geometry
                             std::vector<IfcGeometry> geomVector = {geom}; // Wrap 'geom' in a vector
                             fusedVoids = BoolProcess(std::vector<IfcGeometry>{fusedVoids}, geomVector, "UNION", _settings);
                         }
+                        if (fusedVoids.numFaces > _settings._CSG_MAX_NUM_FACES) {
+                            spdlog::warn("High number of faces ({}) in voids for element {}, skipping further CSG operations", fusedVoids.numFaces, expressID);
+                            break;
+                        }
                     }
 
                     joinedVoidGeoms.push_back(fusedVoids);
@@ -339,6 +343,39 @@ namespace webifc::geometry
                     return mesh;
                 }
 
+                size_t numFacesGeoms = 0;
+                for (auto& geom : flatFirstMeshes) {
+                    numFacesGeoms += geom.numFaces;
+                }
+                for (auto& geom : flatSecondMeshes) {
+                    numFacesGeoms += geom.numFaces;
+                }
+
+                if (numFacesGeoms > _settings._CSG_MAX_NUM_FACES) {
+                    spdlog::warn("High number of faces in CSG operand ({}), skipping further CSG operations", numFacesGeoms);
+
+                    // Flatten the first operand (transformed and normalized, like in the normal path)
+                    auto flatFirstMeshes = flatten(firstMesh, _expressIDToGeometry, normalizeMat);
+
+                    // Merge into a single geometry (equivalent to the first operand without boolean)
+                    IfcGeometry resultMesh;
+                    for (const auto& g : flatFirstMeshes) {
+                        resultMesh.MergeGeometry(g);
+                    }
+
+                    _expressIDToGeometry[expressID] = resultMesh;
+                    mesh.hasGeometry = true;
+                    mesh.transformation = glm::translate(origin);
+
+                    if (!mesh.hasColor && firstMesh.hasColor) {
+                        mesh.hasColor = true;
+                        mesh.color = firstMesh.color;
+                    }
+
+                    // No need to set mesh = firstMesh; we're building a flat geometry here for consistency
+                    return mesh;
+                }
+
                 IfcGeometry resultMesh = BoolProcess(flatFirstMeshes, flatSecondMeshes, std::string(op), _settings);
 
                 _expressIDToGeometry[expressID] = resultMesh;

src/cpp/web-ifc/geometry/IfcGeometryProcessor.h

@@ -34,6 +34,7 @@ namespace webifc::geometry
     double TOLERANCE_INSIDE_OUTSIDE_PERIMETER = 1.0E-10;
     double TOLERANCE_BOUNDING_BOX = 1.0E-02;
     uint16_t _BOOLEAN_UNION_THRESHOLD = 150;
+    uint16_t _CSG_MAX_NUM_FACES = 20000;
   };
 
   class booleanManager