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).

Important Tips

💡💡💡 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 👉 TetWild.

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

@article{Hu:2019:TRT:3306346.3323011,
 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 = {http://doi.acm.org/10.1145/3306346.3323011},
 doi = {10.1145/3306346.3323011},
 acmid = {3323011},
 publisher = {ACM},
 address = {New York, NY, USA},
 keywords = {curved triangulation, mesh generation, robust geometry processing},
}

💡💡💡 Check our license first.

Dataset

💡💡💡 Please kindly cite our paper when using our pre-generated data.

Examples in the Paper

Download zip.

💡💡💡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)

Installation

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 https://github.com/wildmeshing/TriWild

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.

Usage

Input：

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]

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 $\epsilon = \epsilon_r d$ , where 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 $\ell = \ell_r d$ .

License

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.

wildmeshing/TriWild