[Gmsh] New Gmsh release: 2.0.0

[Christophe Geuzaine]

Hi all - We're very happy to announce the release of Gmsh 2.0.0.

The codebase has undergone *major* modifications since Gmsh 1.65 (about
50% of the code is brand new!), so please let us know of any bugs or
incompatibilities you discover in this release.


New features in Gmsh 2.0.0:
---------------------------

- import of STEP, IGES and native OpenCascade models

- new graphics pipeline for geometry and mesh rendering (you should see
large gains in both rendering speed and memory footprint)

- new I/O layer for meshes, with new native binary MSH format and
support for import/export of I-deas universal meshes (UNV), Nastran
bulk data format (BDF), stereo lithography files (STL), Medit meshes
and VRML 1.0 files

- support for incomplete second order elements (8-node quads, etc.) and
second order nodes created by linear interpolation

- improved graphical interface with immediate application of changes in
the option panels and much improved visibility browser

- support for offscreen rendering using OSMesa and support for scalable
vector graphics (SVG) output

- support for string labels for physical groups (for example: Physical
Surface("my name"))


Features missing in this release:
---------------------------------

- the 3D "Netgen" algorithm does not support mesh adaptation

- models imported from external CAD engines cannot be modified

- Plugin(ExtractEdges) has not been reimplemented yet

- the STL remesher has not been reimplemented yet

- the "full-quads" recombine algorithm has not been reimplemented yet


Known bugs:
-----------

- Optimizing meshes generated with the 3D "Delaunay" algorithm can lead
to crashes

- recombined unstructured meshes are sometimes wrong, and the quads can
have the wrong orientation


Backward compatibility issues:
------------------------------

Although we did our best to maintain full backward compatibility with
models created with previous versions, there are a few (relatively
minor) incompatibilities with existing .geo files:

- region numbers cannot be specified explicitly anymore in mesh
extrusions. This feature was already not recommended in previous
versions--and it has been completely removed from Gmsh 2. Instead, you
should use the automatically created region number as follows:

num[] = Extrude {0,0,h} { Surface{6}; Layers{10}; };
// num[0] is the id of the new top surface
// num[1] is the id of new volume

- the old "2D anisotropic" algorithm has been removed. Mesh attractors
have been reimplemented, but their syntax has changed--and since this
change has not been documented yet, just don't use attractors for now...
unless you feel really adventurous ;-)

-- 
Prof. Christophe Geuzaine
University of Liege, Electrical Engineering and Computer Science
http://www.case.edu/artsci/math/geuzaine