Computational Geometry Algorithms Library
The goal of the CGAL Open Source Project is to provide
easy access to efficient and reliable geometric algorithms
in the form of a C++ library.
CGAL is used in various areas needing geometric computation, such as:
computer graphics, scientific visualization, computer aided design and
modeling, geographic information systems, molecular biology, medical imaging,
robotics and motion planning, mesh generation, numerical methods...
More on the projects using CGAL web page.
The Computational Geometry Algorithms Library
(CGAL), offers data
structures and algorithms like
triangulations (2D constrained triangulations and Delaunay triangulations in 2D and 3D, periodic triangulations in 3D),
Voronoi diagrams (for 2D and 3D points, 2D additively weighted Voronoi diagrams, and
segment Voronoi diagrams),
polygons (Boolean operations, offsets, straight skeleton),
polyhedra (Boolean operations),
arrangements of curves and their applications (2D and 3D envelopes, Minkowski sums),
mesh generation (2D Delaunay mesh generation and 3D surface and volume mesh generation, skin surfaces),
geometry processing (surface mesh simplification,
subdivision and parameterization, as well as estimation of local differential properties,
and approximation of ridges and umbilics),
convex hull algorithms (in 2D, 3D and dD),
search structures (kd trees for nearest neighbor search, and range and segment trees),
interpolation (natural neighbor interpolation and placement of streamlines),
shape analysis, fitting, and distances (smallest enclosing sphere of points or spheres, smallest enclosing ellipsoid of points,
principal component analysis), and
kinetic data structures.
All these data structures and algorithms operate on geometric objects
like points and segments, and perform geometric tests on them.
These objects and predicates are regrouped in CGAL
Support Library offers geometric object generators and spatial sorting functions,
as well as a matrix search framework and a solver for linear and quadratic programs.
It further offers interfaces to third party software such as the GUI libraries Qt,
Geomview, and the Boost Graph Library.
CGAL is distributed under a dual-license scheme. CGAL can be used together
with Open Source software free of charge. Using CGAL in other contexts can be
done by obtaining a commercial license from
For more details see the License page.
Older news and announcements
- May 24, 2013
- The CGAL project welcomes 8 GSoC students. Have a look at the Accepted Projects page.
- April 25, 2013
- Job offer: young
- April 16, 2013
The CGAL Project is a mentoring organization for Google Summer of Code 2013.
Have a look at our Project Ideas page.
- April 11, 2013
CGAL-4.2 is released.
Check the changes for details,
- April 1, 2013
We have changed the CGAL logo. Learn more about our
the motivation and alternatives.
- March 6, 2013
Find CGAL related Q&A on stackoverflow.
- October 24, 2012
- CGAL-4.1 is released.
Check the changes for details,
- August 7-9, 2012
Visit the CGAL Project on Booth No. 1014 at the exhibition of Siggraph 2012,
Los Angeles, 7-9 August 2012.
- June 17-20, 2012
Follow CGAL during the CG
Week in Chapel Hill, NC, USA. Two minisymposia:
CGAL, an Open Gate to
and Publicly Available