CGAL users discussion list

[Andreas Fabri <>]

The CGAL Open Source Project is pleased to announce the release 3.3 of
CGAL, the Computational Geometry Algorithms Library.


Besides improvements of existing packages this release offers
the following new algorithms and data structures.


 o Surface Mesh Simplification

  This package provides a mesh simplification framework using edge collapse
  operations, and provides the Turk/Lindstrom simplification algorithm.


 o Estimation of Local Differential Properties

  This package allows to compute local differential quantities of a surface
  from a point sample.


 o Approximation of Ridges and Umbilics on Triangulated Surface Meshes

  This package enables the approximation of differential features on
  triangulated surface meshes. Such curvature related features are
  lines: ridges or crests, and points: umbilics.


 o Envelopes of Curves in 2D

  This package contains two sets of functions that construct the lower and
  upper envelope diagram for a given range of bounded or unbounded curves.


 o Envelopes of Surfaces in 3D

  This package contains two sets of functions that construct the lower and
  upper envelope diagram for a given range of bounded or unbounded surfaces.
  The envelope diagram is realized as a 2D arrangement.


 o Minkowski Sums in 2D

  This package contains functions for computing planar Minkowski sums of two
  closed polygons,  and for a polygon and a disc (an operation also known as
  offsetting or dilating a polygon).
  The package also contains an efficient approximation algorithm for the 
offset
  computation,  which provides a guaranteed approximation bound while 
significantly
  expediting the running times w.r.t. the exact computation procedure.


 o CGAL and the Boost Graph Library

  This package provides the glue layer for several CGAL data structures such
  that they become models of the BGL graph concept.


 o Spatial Sorting

  This package allows to sort points and other objects along a Hilbert curve
  which can improve the performance of algorithms like triangulations.
  It is used by the constructors of the triangulation package which have
  an iterator range of points as argument.


 o Linear and Quadratic Programming Solver

  This package contains algorithms for minimizing linear and convex quadratic
  functions over polyhedral domains, described by linear equations and 
inequalities.



See http://www.cgal.org/releases.html for a complete list of changes.



The CGAL project is a collaborative effort to develop a robust,
easy-to-use, and efficient C++ software library of geometric data
structures and algorithms, like
- triangulations (2D constrained triangulations and Delaunay
  triangulations in 2D and 3D),
- Voronoi diagrams (for 2D and 3D points, 2D additively weighted
  Voronoi diagrams, and segment Voronoi diagrams),
- Boolean operations on polygons and polyhedra,
- Regularized Boolean operations on polygons with curved arcs
- arrangements of curves,
- mesh algorithms (2D Delaunay mesh generation and 3D surface mesh
  generation, surface mesh subdivision and parameterization),
- alpha shapes,
- convex hull algorithms (in 2D, 3D and dD),
- operations on polygons (straight skeleton and offset polygon),
- search structures (kd trees for nearest neighbor search, and
  range and segment trees),
- interpolation (natural neighbor interpolation and placement of
  streamlines),
- optimisation algorithms (smallest enclosing sphere of points or
  spheres, smallest enclosing ellipsoid of points, principal
  component analysis),
- kinetic data structures




Some modules are distributed under the terms of the LGPL Open Source
license(GNU Lesser General Public License v2.1).
Most modules are distributed under the terms of the QPL Open Source
license (Q Public License v1.0).
If your intended usage does not meet the criteria of the
aforementioned licenses, a commercial license must be purchased from
GeometryFactory (www.geometryfactory.com).


For further information and for downloading the library and its
documentation, please visit the CGAL web site: http://www.cgal.org/