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TriWild: Robust Triangulation With Curve Constraints

Yixin Hu, Teseo Schneider, Xifeng Gao, Qingnan Zhou, Alec Jacobson, Denis Zorin, Daniele Panozzo. ACM Transactions on Graphics (SIGGRAPH 2019).

Check it out πŸ‘‰

Build Status Build status Build Status

Important Tips

πŸ’‘πŸ’‘πŸ’‘ We also have 3D version of “TriWild” - TetWild! It’s the parent of TriWild. TetWild can generate linear tetrahedral meshes robustly and automatically. Check it out πŸ‘‰ TetWild.

πŸ’‘πŸ’‘πŸ’‘ If you are interested in the algorithm details, please refer to our paper first. We provide plenty of examples and statistics in the paper.

 author = {Hu, Yixin and Schneider, Teseo and Gao, Xifeng and Zhou, Qingnan and Jacobson, Alec and Zorin, Denis and Panozzo, Daniele},
 title = {TriWild: Robust Triangulation with Curve Constraints},
 journal = {ACM Trans. Graph.},
 issue_date = {July 2019},
 volume = {38},
 number = {4},
 month = jul,
 year = {2019},
 issn = {0730-0301},
 pages = {52:1--52:15},
 articleno = {52},
 numpages = {15},
 url = {},
 doi = {10.1145/3306346.3323011},
 acmid = {3323011},
 publisher = {ACM},
 address = {New York, NY, USA},
 keywords = {curved triangulation, mesh generation, robust geometry processing},

πŸ’‘πŸ’‘πŸ’‘ Check our license first.


πŸ’‘πŸ’‘πŸ’‘ Please kindly cite our paper when using our pre-generated data.

Examples in the Paper

Download zip.

πŸ’‘πŸ’‘πŸ’‘Quickly try TriWild on some small exmaples here!!

20k Openclip Dataset

Input: 19686 meshes (.obj) each with a curved feature file (.json)

(For your reference, here is original 20k SVG images. Those with animation are not converted to obj/json.)

Output with curved constrains: 19685 meshes (.msh)

Output with linear constrains(todo James): 19686 meshes (.msh)


You can use TriWild either by pulling a Docker image or compiling the source code with CMake.

via Docker

Install Docker and run Docker. Pull TetWild Docker image and run the binary:

docker pull yixinhu/triwild
docker run --rm -v "$(pwd)":/data yixinhu/triwild /app/TriWild/build/TriWild [TriWild arguments]

via CMake

Our code was originally developed on MacOS and has been tested on Linux and Windows. We provide the commands for installing TriWild in Unix OS:

  • Clone the repository into your local machine:

git clone
- Compile the code using cmake (default in Release mode):

cd TriWild
mkdir build
cd build
cmake ..
make -j
  • Check the installation:

./TriWild --help
This command should show a list of TriWild parameters.



  • Linear constraints (required): segment soup in .obj format.

  • Curved constraints: Bezier curves in .json format.

Output: Linear/high-order triangle mesh in .msh format.

Please check dataset above for examples.

Quick Try

You can try TriWIld quickly with default parameters by running

./TriWild --input input.obj
for linear constrains, or

./TriWild --input input.obj --feature-input input.json
for curved constrains.

Command Line Switches

Usage: ./TriWild [OPTIONS]

  -h,--help                   Print this help message and exit
  --input TEXT (REQUIRED)     Input segments in .obj format.
  --output TEXT               Output path.
  --postfix TEXT              Add postfix into outputs' file name.
  --feature-input TEXT        Input feature json file.
  --stop-quality FLOAT        Specify max AMIPS energy for stopping mesh optimization.
  --max-its INT               Max number of mesh optimization iterations.
  --stage INT                 Specify envelope stage
  --envelope-r FLOAT          relative envelope epsilon_r. Absolute epsilonn = epsilon_r * diagonal_of_bbox
  --feature-envelope-r FLOAT  Relative feature envelope mu_r. Absolute mu = mu_r * diagonal_of_bbox
  --target-edge-length FLOAT  Absolute target edge length l.
  --target-edge-length-r FLOAT
                              Relative target edge length l_r. Absolute l = l_r * diagonal_of_bbox
  --log-file TEXT             Output a log file.
  --min-angle FLOAT           Desired minimal angle.
  --mute-log                  Mute prints.
  --cut-outside               Remove "outside part".
  --skip-eps                  Skip saving eps.
  --cut-holes TEXT            Input a .xyz file for specifying points inside holes you want to remove.
  --output-linear-mesh        Output linear mesh for curved pipeline.

More details about some important parameters:

  • --feature-input

We provide a python script for converting a svg to curves in .json format.

  • --envelope

Relative surface envelope \epsilon_r (1e-3 in default). Absolute surface envelope \epsilon_r d, where d is the length of the diagonal of the bounding box of input.

  • --feature-envelope

Relative feature envelope \mu_r (1e-3 in default with linear constraints and 2e-3 for curved constraints). Absolute feature envelope \mu = \mu_r d.

  • --target-edge-length-r

Relative targeted edge length \ell_r (0.05 in default). Absolute targeted edge length \ell = \ell_r d.


TriWild is MPL2 licensed and free for both commercial and non-commercial usage. However, you have to cite our work in your paper or put a reference of TriWild in your software. Whenever you fix bugs or make some improvement of TriWild, you should contribute back.