JIGSAW: An unstructured mesh generator
JIGSAW is a computational library for unstructured mesh generation; designed to generate high-quality triangulations and polyhedral decompositions of general planar, surface and volumetric domains. JIGSAW includes both refinement-based algorithms for the construction of new meshes, as well as optimisation-driven techniques for the improvement of existing grids.
This package provides a MATLAB / OCTAVE based scripting interface to the underlying JIGSAW mesh generator, including a range of additional facilities for file I/O, mesh visualisation and post-processing operations.
JIGSAW has been compiled and tested on various 64-bit Linux , Windows and Mac based platforms.
Code Structure
JIGSAW is a multi-part library, consisting of a MATLAB / OCTAVE front-end, and a core c++ back-end. All of the heavy-lifting is done in the c++ layer - the interface contains additional scripts for file I/O, visualisation and general data processing:
├── JIGSAW :: MATLAB/OCTAVE top-level functions
├── script -- MATLAB/OCTAVE utilities
└── jigsaw
├── src -- JIGSAW source files
├── inc -- JIGSAW header files (for libjigsaw)
├── bin -- put JIGSAW exe binaries here
├── lib -- put JIGSAW lib binaries here
├── geo -- default folder for JIGSAW inputs
├── out -- default folder for JIGSAW output
└── uni -- unit tests and libjigsaw programs
The MATLAB / OCTAVE interface is provided for convenience - you're not forced to use it, but it's perhaps the easiest way to get started!
It's also possible to interact with the JIGSAW back-end directly, either through (i) scripting: building text file inputs and calling the JIGSAW executable from the command-line, or (ii) programmatically: using JIGSAW data-structures within your own applications and calling the library via its API.
Getting Started
The first step is to compile the code! The JIGSAW src can be found in ../jigsaw/src/.
JIGSAW is a header-only package - there is only the single main jigsaw.cpp file that simply #include's the rest of the library as headers. The resulting build process should be fairly straight-forward as a result. JIGSAW does not currently dependent on any external packages or libraries.
On Linux/Mac
JIGSAW has been successfully built using various versions of the g++ and llvm compilers. Since the build process is a simple one-liner, there's no make script - instead:
g++ -std=c++11 -pedantic -Wall -s -O3 -flto -D NDEBUG -static-libstdc++
jigsaw.cpp -o jigsaw64r
can be used to build a JIGSAW executable, while:
g++ -std=c++11 -pedantic -Wall -O3 -flto -fPIC -D NDEBUG -static-libstdc++
jigsaw.cpp -shared -o libjigsaw64r.so
can be used to build a JIGSAW shared library. See the headers in ../jigsaw/inc/ for details on the API. The #define __lib_jigsaw directive in jigsaw.cpp toggles the source between executable and shared-library modes.
On Windows
JIGSAW has been successfully built using various versions of the msvc compiler. I do not provide a sample msvc project, but the following steps can be used to create one:
* Create a new, empty MSVC project.
* Import the jigsaw.cpp file, this contains the main() entry-point.
Folder Structure
Once you have built the JIGSAW binaries, place them in the appropriate sub-folders in../jigsaw/bin/ and/or ../jigsaw/lib/ directories, so that they can be found by the MATLAB / OCTAVE interface, and the unit tests in ../jigsaw/uni/. If you wish to support multiple platforms, simply build binaries for each OS and place them in the appropriate directory - the MATLAB / OCATVE interface will do an OS-dependent lookup to call the appropriate binary.
Example Problems
After compiling and configuring the code, navigate to the JIGSAW installation directory in your MATLAB / OCTAVE environment and run the following set of example problems:
meshdemo(1); % build surface-meshes
meshdemo(2); % build volume-meshes
meshdemo(3); % preserve "sharp-features" in piecewise smooth domains
meshdemo(4); % build planar-meshes -- impose topological constraints
meshdemo(5); % build planar-meshes -- explore mesh-size controls
meshdemo(6); % mesh iso-surface geometry -- case 1
meshdemo(7); % mesh iso-surface geometry -- case 2
Additional information, documentation, online tutorials and references are available here. A repository of 3D surface models generated using JIGSAW can be found here.
License
This program may be freely redistributed under the condition that the copyright notices (including this entire header) are not removed, and no compensation is received through use of the software. Private, research, and institutional use is free. You may distribute modified versions of this code UNDER THE CONDITION THAT THIS CODE AND ANY MODIFICATIONS MADE TO IT IN THE SAME FILE REMAIN UNDER COPYRIGHT OF THE ORIGINAL AUTHOR, BOTH SOURCE AND OBJECT CODE ARE MADE FREELY AVAILABLE WITHOUT CHARGE, AND CLEAR NOTICE IS GIVEN OF THE MODIFICATIONS. Distribution of this code as part of a commercial system is permissible ONLY BY DIRECT ARRANGEMENT WITH THE AUTHOR. (If you are not directly supplying this code to a customer, and you are instead telling them how they can obtain it for free, then you are not required to make any arrangement with me.)
DISCLAIMER: Neither I nor: Columbia University, the Massachusetts Institute of Technology, the University of Sydney, nor the National Aeronautics and Space Administration warrant this code in any way whatsoever. This code is provided "as-is" to be used at your own risk.
Attribution!
If you make use of JIGSAW please make reference to the following papers. The algorithmic developments behind JIGSAW have been the subject of a number of publications, originally stemming from my PhD research at the University of Sydney:
[1] - Darren Engwirda: Generalised primal-dual grids for unstructured co-volume schemes, J. Comp. Phys., 375, pp. 155-176, https://doi.org/10.1016/j.jcp.2018.07.025, 2018.
[2] - Darren Engwirda, Conforming Restricted Delaunay Mesh Generation for Piecewise Smooth Complexes, Procedia Engineering, 163, pp. 84-96, https://doi.org/10.1016/j.proeng.2016.11.024, 2016.
[3] - Darren Engwirda, Voronoi-based Point-placement for Three-dimensional Delaunay-refinement, Procedia Engineering, 124, pp. 330-342, http://dx.doi.org/10.1016/j.proeng.2015.10.143, 2015.
[4] - Darren Engwirda, David Ivers, Off-centre Steiner points for Delaunay-refinement on curved surfaces, Computer-Aided Design, 72, pp. 157-171, http://dx.doi.org/10.1016/j.cad.2015.10.007, 2016.
[5] - Darren Engwirda, Locally-optimal Delaunay-refinement and optimisation-based mesh generation, Ph.D. Thesis, School of Mathematics and Statistics, The University of Sydney, http://hdl.handle.net/2123/13148, 2014.