CGAL 6.1

The CGAL Open Source Project is pleased to announce the release 6.1 of CGAL, the Computational Geometry Algorithms Library.

Besides fixes and general enhancement to existing packages, the following has changed since CGAL 6.0:

General Changes

• The new list of supported compilers is:
  • Visual C++ 15.9, 16.10, 17.0 (from Visual Studio 2017, 2019 and 2022) or later
  • Gnu g++ 12.2.0 or later (on Linux)
  • LLVM Clang version 20.1.6 or later (on Linux)
  • Apple Clang compiler versions 12.0.5 and 12.0.5 (on macOS)
• The minimal supported version of Boost is now 1.74.0.

3D Constrained Triangulations (new package)

• This package implements the construction of a 3D Constrained Delaunay triangulation. This triangulation is a generalization of a 3D Delaunay Triangulation which conforms to the set of faces of a 3D piecewise linear complex (PLC), ensuring that these faces are part of the triangulation. As not all PLCs are tetrahedralizable, the algorithm may insert Steiner points to construct the constrained triangulation. The main entry point is the function CGAL::make_conforming_constrained_Delaunay_triangulation_3().

3D Isosurfacing (new package)

• This package provides algorithms to extract isosurfaces from scalar fields. The algorithms provided in this first version include Marching Cubes, Topologically Correct Marching Cubes, and Dual Contouring. The algorithm is generic with respect to the scalar field representation (implicit function, discrete values, …) and the discretization data structure (Cartesian grid, octree, …). The output is an indexed face set that stores an isosurface in the form of a surface mesh.

dD Fréchet Distance (new package)

• This package provides functions for computing the Fréchet distance of polylines in any dimension under the Euclidean metric.

2D Triangulations on Hyperbolic Surfaces (new package)

• This package enables building and handling triangulations of closed orientable hyperbolic surfaces. It offers functions for the generation of the triangulation from a convex fundamental domain, the Delaunay flip algorithm, and the construction of a portion of the lift of the triangulation in the Poincaré disk. A method is offered that generates such domains in genus two.

  See also the associated news entry.

Polygon Repair

• Added the non-zero rule (areas with non-zero winding number are kept), as well as two functions to compute the conservative inner and outer hull of similar polygons:

  • CGAL::Polygon_repair::join()
  • CGAL::Polygon_repair::intersect()

  See also the associated news entry.

Polygon Mesh Processing

• Added the parameter apply_iterative_snap_rounding to the function CGAL::Polygon_mesh_processing::autorefine_triangle_soup(). When set to true, the coordinates are rounded to fit in double and may perform additional subdivisions to ensure the output is free of self-intersections. See also the associated news entry.
• Added the function CGAL::Polygon_mesh_processing::approximated_centroidal_Voronoi_diagram_remeshing() to remesh triangle meshes. This remeshing algorithm uses clustering on polygonal meshes as to approximate a Centroidal Voronoi Diagram construction, and can move vertices as to recover sharp features and corners. See also the associated news entry.
• New implementation of CGAL::Polygon_mesh_processing::clip() and CGAL::Polygon_mesh_processing::split() with a plane as clipper that is much faster and is now able to handle non-triangulated surface meshes. See also the associated news entry.
• Added the function CGAL::Polygon_mesh_processing::refine_with_plane(), which enables users to refine a mesh with its intersection with a plane.
• Added a function in the visitor of the corefinement based methods to trace faces in the output meshes which correspond to coplanar faces of the input.
• Added the function CGAL::Polygon_mesh_processing::discrete_mean_curvature() and CGAL::Polygon_mesh_processing::discrete_Gaussian_curvature() to evaluate the discrete curvature at a vertex of a mesh.
• Added the function CGAL::Polygon_mesh_processing::angle_sum() to compute the sum of the angles around a vertex.

Point Set Processing

• Added CGAL::poisson_eliminate(), which can be used to downsample a point cloud to a target size while providing Poisson disk property, i.e., a larger minimal distance between points.

CGAL and the Boost Graph Library (BGL)

• Added the function dijkstra_shortest_path(), which can be used to compute the geometrically shortest sequence of halfedges between two vertices.
• Added the function CGAL::Euler::remove_degree_2_vertex(), which enables users to remove vertices which have exactly two incident edges.

2D Arrangements

• Breaking change: Renamed the concept AosApproximateTraits_2 to AosApproximatePointTraits_2 to make room for the new concept AosApproximateTraits_2. This concept requires the provision of a functor called Approximate_2 that has an operator that approximates the coordinates of a point.
• Breaking change: The concept AosApproximateTraits_2 now refines the concept AosApproximatePointTraits_2 and requires the provision of a functor called Approximate_2. In addition to an operator that approximates the coordinates of a point, it also requires the provision of (i) an operator that approximates a points, and (ii) an operator that approximates a curve.
• Renamed the prefix of the names of all concepts in the Arrangement_on_surface_2 package from “Arrangement” to “Aos”.
• Introduced two traits decorators, namely CGAL::Arr_tracing_traits_2 and CGAL::Arr_counting_traits_2, which can be used to extract debugging and informative metadata about the traits in use while a program is being executed.
• Fixed the Landmark point-location strategy so that it can be applied to arrangements on a sphere.
• Fixed a bug in the extensions of vertex and halfedge types of the DCEL when used to instantiate Arrangement_with_history_2 or similar arrangement classes that derive from Arrangement_2.
• Fixed do_intersect() of a 2D Arrangement with a curve.

Triangulations

• All triangulations now offer the functions point(Vertex_handle) and point(Simplex, int), which enables users to access the geometric position of a vertex and of the i-th vertex of a simplex of a triangulation.

Poisson Surface Reconstruction

• Added a new mesh domain Poisson_mesh_domain_3 that integrates some optimizations from the deprecated 3D Surface Mesh Generation package.

...

CGAL 6.0.2

CGAL-6.0.2 is a bug-fix release.

See on Github the list of bugs that were solved since CGAL-6.0.1.

Full Changelog: v6.0.1...v6.0.2

CGAL 6.1-beta2

The CGAL Open Source Project is pleased to announce the release 6.1 Beta 2 of CGAL, the Computational Geometry Algorithms Library.

CGAL version 6.1 Beta 2 is a public testing release. It should provide a solid ground to report bugs that need to be tackled before the release of the final version of CGAL 6.1 in Sept 2025.

The changelog is available at https://www.cgal.org/2025/09/17/cgal61-beta2/.

CGAL 5.6.3

CGAL-5.6.3 is a bug-fix release.

See on Github the list of bugs that were solved since CGAL-5.6.2.

CGAL 6.1-beta1

The CGAL Open Source Project is pleased to announce the release 6.1 Beta 1 of CGAL, the Computational Geometry Algorithms Library.

CGAL version 6.1 Beta 1 is a public testing release. It should provide a solid ground to report bugs that need to be tackled before the release of the final version of CGAL 6.1 in Sept 2025.

Change log available at https://www.cgal.org/2025/07/07/cgal61-beta1/.

CGAL 5.6.2

CGAL-5.6.2 is a bug-fix release.

See on Github the list of bugs that were solved since CGAL-5.6.1.

CGAL 5.5.5

CGAL-5.5.5 is a bug-fix release.

See on Github the list of bugs that were solved since CGAL-5.5.4.

CGAL 6.0.1

CGAL-6.0.1 is a bug-fix release.

See on Github the list of bugs that were solved since CGAL-6.0.

Full Changelog: v6.0...v6.0.1

CGAL 6.0

The CGAL Open Source Project is pleased to announce the release 6.0 of CGAL, the Computational Geometry Algorithms Library.

Besides fixes and general enhancement to existing packages, the following has changed since CGAL 5.6:

General Changes

• CGAL 6.0 is the first release of CGAL that requires a C++ compiler with the support of C++17 or later. The new list of supported compilers is:

  • Visual C++ 15.9, 16.10, 17.0 (from Visual Studio 2017, 2019 and 2022) or later
  • Gnu g++ 11.4.0 or later (on Linux or macOS)
  • LLVM Clang version 15.0.7 or later (on Linux)
  • Apple Clang compiler versions 10.0.1, 12.0.5, and 15.0.0 (on macOS)

• The minimal supported version of Boost is now 1.72.0.

• GMP/MPFR are no longer mandatory to use CGAL, Boost.Multiprecision. can be used instead.

• The CGAL Core library is no longer based on GMP, but on Boost.Multiprecision. Either GMP backend or Boost backend can be used.

• All demos are now based on Qt6.

• Breaking change: The CMake file UseCGAL.cmake has been removed from CGAL. Usages of the CMake variables ${CGAL_USE_FILE} and ${CGAL_LIBRARIES} must be replaced by a link to the imported target CGAL::CGAL, for example:

      target_link_library(your_target PRIVATE CGAL::CGAL)

Kinetic Space Partition (new package)

• This package implements kinetic space partition: based on a set of planar input shapes, the bounding box of the input data is split into convex volumes. The complexity of the partition can be adjusted with a single parameter.

Kinetic Surface Reconstruction (new package)

• The package implements a piece-wise planar surface reconstruction pipeline from point clouds combining methods from the Shape Detection, Shape Regularization and Kinetic Shape Partition packages and graph-cut to reconstruct surfaces from point clouds.

Basic Viewer (new package)

• The basic viewer package provides interactive visualization for most CGAL packages, such as 2D Arrangements, 2D Regularized Boolean Set-Operations, Linear Cell Complex, 3D Boolean Operations on Nef Polyhedra, 2D Periodic Triangulations, 3D Point Set, 2D Polygons, 3D Polyhedral Surface, 2D Straight Skeleton and Polygon Offsetting, Surface Mesh, 2D Triangulations, 3D Triangulations, 2D Voronoi Diagrams, and more. The most simple use case of the basic viewer is the call of the global CGAL::draw() function. There is one such draw() function for each CGAL package that has a basic viewer. Such a call opens an interactive window showing the given model and allowing to navigate in the scene, show or hide some specific cells, show the interior of the model if any, etc. The Basic_viewer is based on Qt6.

Polygon Repair (new package)

• This package provides algorithms to repair 2D polygons, polygons with holes, and multipolygons with holes, by selecting faces of the arrangement of the input using the odd-even heuristic.

2D and 3D Linear Geometry Kernel

• Breaking change: Replaced all instances of boost::variant with std::variant in the intersection functions.
• Breaking change: Replaced all instances of boost::optional with std::optional in the intersection functions.

3D Polyhedral Surface

• The demo of this package, also known as “Polyhedron Demo” has been renamed “CGAL Lab” and moved to its own package (“Lab”).

2D and 3D Fast Intersection and Distance Computation (AABB Tree)

• The AABB tree can now be used with 2D or 3D primitives:
  • The concepts AABBGeomTraits and AABBRayIntersectionGeomTraits have been replaced by AABBGeomTraits_3 and by AABBRayIntersectionGeomTraits_3, respectively.
  • The concepts AABBGeomTraits_2 and AABBRayIntersectionGeomTraits_2 have been introduced, as the 2D counterparts.
  • The class CGAL::AABB_traits is deprecated and replaced by CGAL::AABB_traits_3.
  • The class CGAL::AABB_traits_2 is introduced as the 2D counterpart.
  • The class CGAL::AABB_segment_primitive has been deprecated and replaced by the class CGAL::AABB_segment_primitive_3.
  • The class CGAL::AABB_triangle_primitive has been deprecated and replaced by the class CGAL::AABB_triangle_primitive_3.
  • The following 2D primitive classes have been added: CGAL::AABB_segment_primitive_2, CGAL::AABB_polyline_segment_primitive_2, CGAL::AABB_triangle_primitive_2, CGAL::AABB_indexed_triangle_primitive_2.
• Breaking change: The concept AABBTraits now refines the concept SearchTraits.
• Breaking change: Replaced all instances of boost::optional with std::optional.

2D Arrangements

• Breaking change: Replaced all instances of boost::variant with std::variant.
• Breaking change: The type of the result of point location queries has been changed to std::variant. Support for the old macro CGAL_ARR_POINT_LOCATION_VERSION has been removed.
• Breaking change: Eliminated the error-prone C-type casting that was used to define observers. In general, backward compatibility was maintained; however, the class template CGAL::Arr_observer has been replaced by an alias template. (The class CGAL::Arr_observer was renamed to CGAL::Aos_observer).
• Introduced Arr_dcel, which essentially replaces the former CGAL::Arr_default_dcel. Backward compatibility was maintained by the introduction of the alias template CGAL::Arr_default_dcel. CGAL::Arr_dcel, as opposed to the former CGAL::Arr_default_dcel is templated (in addition to the geometry traits) by Vertex, Halfedge, and Face template parameters, and they have default type values. All this enables the layered extension of DCEL records.
• Fixed a bug in the zone construction code applied to arrangements of geodesic arcs on a sphere, when inserting an arc that lies on the identification curve.
• Introduced a new interactive program that demonstrates 2D arrangements embedded on the sphere called earth. The program (i) reads a database of all administrative boundaries of the countries in the world, (ii) displays the globe with all countries and land covered by water (which is land not covered by countries) on a window, and (ii) enables interaction with the user.

3D Envelopes

• Breaking change: [Construct_projected_boundary_2](https://d...

CGAL 6.0-beta1

The CGAL Open Source Project is pleased to announce the release 6.0 Beta 1 of CGAL, the Computational Geometry Algorithms Library.

CGAL version 6.0 Beta 1 is a public testing release. It should provide a solid ground to report bugs that need to be tackled before the release of the final version of CGAL 6.0 in July 2024.

Besides fixes and general enhancement to existing packages, the following has changed since CGAL 5.6:

General Changes

• CGAL 6.0 is the first release of CGAL that requires a C++ compiler with the support of C++17 or later. The new list of supported compilers is:
  • Visual C++ 15.9, 16.10, 17.0 (from Visual Studio 2017, 2019 and 2022) or later
  • Gnu g++ 11.4.0 or later (on Linux or macOS)
  • LLVM Clang version 15.0.7 or later (on Linux)
  • Apple Clang compiler versions 10.0.1, 12.0.5, and 15.0.0 (on macOS)
• The minimal supported version of Boost is now 1.72.0.
• The CGAL Core library is no longer based on GMP, but on Boost.Multiprecision. Either GMP backend or Boost backend can be used.
• All demos are now based on Qt6.
• Breaking change: The CMake file UseCGAL.cmake has been removed from CGAL. Usages of the CMake variables ${CGAL_USE_FILE} and ${CGAL_LIBRARIES} must be replaced by a link to the imported target CGAL::CGAL, for example: target_link_library(your_target PRIVATE CGAL::CGAL).

Kinetic Space Partition (new package)

• This package implements kinetic space partition: based on a set of planar input shapes, the bounding box of the input data is split into convex volumes. The complexity of the partition can be adjusted with a single parameter.

Kinetic Surface Reconstruction (new package)

• The package implements a piece-wise planar surface reconstruction pipeline from point clouds combining methods from the Shape Detection, Shape Regularization and Kinetic Shape Partition packages and graph-cut to reconstruct surfaces from point clouds.

Basic Viewer (new package)

• The basic viewer package provides interactive visualization for most CGAL packages, such as 2D Arrangements, 2D Regularized Boolean Set-Operations, Linear Cell Complex, 3D Boolean Operations on Nef Polyhedra, 2D Periodic Triangulations, 3D Point Set, 2D Polygons, 3D Polyhedral Surface, 2D Straight Skeleton and Polygon Offsetting, Surface Mesh, 2D Triangulations, 3D Triangulations, 2D Voronoi Diagrams, and more. The most simple use case of the basic viewer is the call of the global CGAL::draw() function. There is one such draw() function for each CGAL package that has a basic viewer. Such a call opens an interactive window showing the given model and allowing to navigate in the scene, show or hide some specific cells, show the interior of the model if any, etc. The Basic_viewer is based on Qt6.

Polygon Repair (new package)

• This package provides algorithms to repair 2D polygons, polygons with holes, and multipolygons with holes, by selecting faces of the arrangement of the input using the odd-even heuristic.

2D and 3D Linear Geometry Kernel

• Breaking change: Replaced all instances of boost::variant with std::variant in the intersection functions.
• Breaking change: Replaced all instances of boost::optional with std::optional in the intersection functions.

3D Polyhedral Surface

• The demo of this package, also known as “Polyhedron Demo” has been renamed “CGAL Lab” and moved to its own package (“Lab”).

2D and 3D Fast Intersection and Distance Computation (AABB Tree)

• The AABB tree can now be used with 2D or 3D primitives:
  • The concepts AABBGeomTraits and AABBRayIntersectionGeomTraits have been replaced by AABBGeomTraits_3 and by AABBRayIntersectionGeomTraits_3, respectively.
  • The concepts AABBGeomTraits_2 and AABBRayIntersectionGeomTraits_2 have been introduced, as the 2D counterparts.
  • The class CGAL::AABB_traits is deprecated and replaced by CGAL::AABB_traits_3.
  • The class CGAL::AABB_traits_2 is introduced as the 2D counterpart.
  • The class CGAL::AABB_segment_primitive has been deprecated and replaced by the class CGAL::AABB_segment_primitive_3.
  • The class CGAL::AABB_triangle_primitive has been deprecated and replaced by the class CGAL::AABB_triangle_primitive_3.
  • The following 2D primitive classes have been added: CGAL::AABB_segment_primitive_2, CGAL::AABB_polyline_segment_primitive_2, CGAL::AABB_triangle_primitive_2, CGAL::AABB_indexed_triangle_primitive_2.
• Breaking change: The concept AABBTraits now refines the concept SearchTraits.
• Breaking change: Replaced all instances of boost::optional with std::optional.

2D Arrangements

• Breaking change: Replaced all instances of boost::variant with std::variant.
• Breaking change: The type of the result of point location queries has been changed to std::variant. Support for the old macro CGAL_ARR_POINT_LOCATION_VERSION has been removed.
• Breaking change: Eliminated the error-prone C-type casting that was used to define observers. In general, backward compatibility was maintained; however, the class template CGAL::Arr_observer has been replaced by an alias template. (The class CGAL::Arr_observer was renamed to CGAL::Aos_observer).
• Introduced Arr_dcel, which essentially replaces the former CGAL::Arr_default_dcel. Backward compatibility was maintained by the introduction of the alias template CGAL::Arr_default_dcel. CGAL::Arr_dcel, as opposed to the former CGAL::Arr_default_dcel is templated (in addition to the geometry traits) by Vertex, Halfedge, and Face template parameters, and they have default type values. All this enables the layered extension of DCEL records.
• Fixed a bug in the zone construction code applied to arrangements of geodesic arcs on a sphere, when inserting an arc that lies on the identification curve.
• Introduced a new interactive program that demonstrates 2D arrangements embedded on the sphere called earth. The program (i) reads a database of all administrative boundaries of the countries in the world, (ii) displays the globe with all countries and land covered by water (which is land not covered by countries) on a window, and (ii) enables interaction with the user.

3D Envelopes

• Breaking change: [Construct_projected_boundary_2](https://...