Visualization of non-convex polyhedra and pattern generating for paper building. Display non-convex polyhedra. GSolaar is an open source software, an utility that manages solids whose polyhedron are sort of, its main functions are:
1. Visualization, handling, navigation of these solids
2. Treatment of non convex stellated polyhedra
3. Generation of patterns for paper buildings (in ps or svg output)
4. Generation of Ruby scripts in order to get the solids in SketchUp

GSolaar provides visualisation of polyhedra and generation of their pattern (in PostScript and SVG) in order to build a paper form according to some restrictions (see "How the program works").
This project follows a study and research work done at the Universit de Nantes that was surrounded by Philippe Martin.

It uses "kaleido" program by Dr. Zvi Har'El from the Department of Mathematics, Technion at the Israel Institute of Technology, providing generation of uniform polyhedra under adjacence matrices model.

The "saa" sublibrary provides generation, visualization and processing of this polyhedra according to a "winged-edge" mode. The "gtk" sublibrary implements widgets to handle polyhedra.

How to use the program
GSolaar project provides two executables:
* solaar : command line processing program -> see solaar man page
* gsolaar : visualization and processing GUI program

How the program works
All polyhedra paterns can't be directly generated, in particular non-convex polyhedra in which faces cut across each other.

For unoriented polyhedra, the "winged-edge" model was summoned to avoid them but then it was proved that some of them was supporting this model (example : #8 Octahemioctahedron). So users still have to detect them.

Lastly, notice that polyhedra that suits usage of processes must have a star shape (ie : every vertex must be visible from the center of the solid).

The implemented process have to keep the visible part of a polyhedron faces (from outside), this is done in three main operations:
1. Cut up cutting across faces
2. Eliminate internal faces
3. Merge face pieces

The license of this software is Free, you can free download and free use this 3d graphic software.