CSXCAD

CSXCAD (Continuous Structure XML CAD) is a C++ library for describing geometrical objects and their physical or non-physical properties. It is designed as a standalone, reusable geometry and material description library suitable for electromagnetic simulation tools and similar applications.

Licensed under the LGPLv3.

Documentation: docs.openems.de

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Dependencies

• CMake ≥ 3.0
• C++11 compiler (GCC, Clang, MSVC)
• fparser — parametric expression evaluation
• TinyXML — XML serialization
• HDF5 — discrete material file I/O
• VTK — geometry export
• CGAL — polyhedron operations

Note: The git clone must be deep (not shallow). CMake uses git describe --tags --always for the version string and will fail on shallow clones.

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Build and Install (C++ Library)

mkdir build && cd build
cmake .. -DCMAKE_INSTALL_PREFIX=~/opt -DFPARSER_ROOT_DIR=~/opt
make -j$(nproc)
make install

Optional local CMake overrides can be placed in localConfig.cmake at the repo root (gitignored).

Windows

On Windows, vcpkg is used for TinyXML, HDF5, VTK, and CGAL (see vcpkg.json):

cmake .. -DCMAKE_TOOLCHAIN_FILE=$VCPKG_ROOT/scripts/buildsystems/vcpkg.cmake

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Python Bindings

The python/ directory contains Cython bindings. The C++ library must be built and installed first.

export CSXCAD_INSTALL_PATH=~/opt
cd python
pip3 install .

Always run tests or scripts from outside the python/ source directory to avoid accidentally importing the uncompiled source instead of the installed extension.

Quick Example

from CSXCAD.CSXCAD import ContinuousStructure

csx = ContinuousStructure()

# Add a metal property with a box primitive
metal = csx.AddMetal('copper')
metal.AddBox(start=[-1, -1, -1], stop=[1, 1, 1])

# Set background material
bg = csx.GetBackgroundMaterial()
bg.SetEpsilon(1.0)

# Serialize to XML (readable by any tool that supports the CSXCAD format)
csx.Write2XML('my_structure.xml')

Running the Tests

cd python/tests
python3 -m unittest

Run a single module or test case:

python3 -m unittest test_CSPrimitives
python3 -m unittest test_CSPrimitives.TestCSPrimitives.test_box

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Matlab / Octave Interface

The matlab/ directory contains a pure M-file interface (no compilation required). It builds the CSX data structure as a Matlab/Octave struct and writes it to XML for consumption by CSXCAD.

Add the matlab/ directory to your Matlab/Octave path:

addpath('/path/to/CSXCAD/matlab');

Basic usage:

CSX = InitCSX();
CSX = AddMetal(CSX, 'copper');
CSX = AddBox(CSX, 'copper', 10, [-1 -1 -1], [1 1 1]);
WriteCSX('my_structure.xml', CSX);

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Related Projects

• openEMS — FDTD simulator using CSXCAD for geometry input
• openEMS-Project — meta-repository combining openEMS and all its dependencies including CSXCAD