TrulySeamless3D is an implementation of the parametrization sanitization procedure described in Sec. 6 of The 3D Motorcycle Complex for Structured Volume Decomposition [Brückler et al. 2021] (accepted to Eurographics 2022) distributed under GPLv3. It is a 3D generalization of the 2D method from Exact Constraint Satisfaction for Truly Seamless Parametrization [Mandad and Campen 2019].

If you make use of TrulySeamless3D in your scientific work, please cite our paper:

@article{DBLP:journals/corr/abs-2112-05793,
    author     = {Hendrik Br{\"{u}}ckler and
                 Ojaswi Gupta and
                 Manish Mandad and
                 Marcel Campen},
    title      = {The 3D Motorcycle Complex for Structured Volume Decomposition},
    journal    = {CoRR},
    volume     = {abs/2112.05793},
    year       = {2021},
    url        = {https://arxiv.org/abs/2112.05793},
    eprinttype = {arXiv},
    eprint     = {2112.05793},
}

TrulySeamless3D takes as input a tetrahedral mesh with an almost seamless parametrization (seamless up to small numerical inaccuracies, as commonly arising in the generation process) and makes it truly seamless. In this way, it enables the use of a wide range of almost-seamless parametrizations for applications that depend on the exact satisfaction of seamlessness constraints.

• Eigen (Not included. Must be installed on your system.)
• OpenVolumeMesh (Included as submodule)
• libHexEx (Included as submodule)

In root directory

mkdir build
cd build
cmake [-DTRULYSEAMLESS_BUILD_CLI=Off] ..
make

A command-line application is included that reads a tetrahedral mesh including an almost-seamless parametrization from a file in .hexex-format, as used and documented in libHexEx. It outputs a file in the same format, containing a (numerically sanitized) truly seamless version of the input.

After building, the CLI app can be found in build/Build/bin . Use as follows:

./TrulySeamless3D /path/to/input/almost-seamless-map.hexex [--preserve-cut-graph]

--preserve-cut-graph will avoid the cut graph getting altered during sanitization, i.e. non-identity transitions will not be moved onto other facets. Preserving the cut graph may slightly speedup sanitization if the input cut graph is already simple, but may (strongly) deteriorate performance if it is far from simple (e.g. cutting the mesh into many charts, rather than just one). If this flag is not used, internally a relatively simple cut graph will be computed, and transitions be moved onto it. The output will be saved to /path/to/input/almost-seamless-map.hexex-seamless.hexex.

Call the constructor TrulySeamless3D(tetmesh, parameters), providing the tetrahedral mesh (of OpenVolumeMesh type) and the (u,v,w) parameters per tet corner (as a map with key tuples (tetID, vertexID)). Then call sanitize(), and finally retrieve the sanitized parametrization map via parameter(CellHandle ch, VertexHandle vh).