Ruben Vons - 6285880 Moritz Cermann - 6562906 Artemi Kurski - 6195784

Files

• report.pdf — assignment report
• src/main.cpp, include/structs.h, CMakeLists.txt — source code
• data/2022020320211122Wellness center Sama.ifc — original IFC input
• data/WellnessCenterSama_simplified.obj — intermediate OBJ (generated by IfcConvert, see below)
• data/mybuilding.city.json — output CityJSON
• additionally, data has subfolders corresponding to different voxel sizes and surface extraction methods.

Dependencies

• CGAL >= 6.1
• Eigen3
• C++17

To compile and run

$ mkdir build
$ cd build
$ cmake ..
$ make
$ ./assignment3

Note that the paths to the input and output file are hardcoded, and the expected input file is data/WellnessCenterSama_simplified.obj

The voxel size is also hardcoded, as double n = 0.25; near the top of main(). This is the value used to generate the submitted mybuilding.city.json.

To replicate the conversion, use IfcConvert, available at https://docs.ifcopenshell.org/ifcconvert/installation.html. Unzip the archive.

cd path/to/unzipped-folder
./IfcConvert --use-element-names --include entities IfcWall IfcRoof IfcFooting IfcWindow IfcDoor IfcStairFlight IfcSlab IfcMember IfcPlate --exclude attribute Name "Floor:Generic 150mm - Filled:348347" attribute Name "Floor:Street:348398" -v path/to/2022020320211122Wellness center Sama.ifc path/to/WellnessCenterSama_simplified.obj"

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By default, main() runs the flood-fill + room filtering + voxel-based surface extraction pipeline (Section 4.4.2). To instead run the mesh-based extraction (Section 4.4.3), comment out:

ExtractedBoundaries boundaries = extract_surfaces(grid, n, origin_x, origin_y, origin_z, num_rooms);

and uncomment:

//ExtractedBoundaries boundaries = extract_boundaries(mesh);