Way back in 1994 I realized that the web could be described as a
directed graph, whose nodes are documents and whose branches are links.
I wrote software that drew these graphs, but it didn't work well because
of the huge amount of interconnection.
Webviz solves this problem by using hyperbolic geometry.
This is just one of my several run-ins with computational geometry.
Geomview is an interactive 3D geometry
viewing program originally written at The Geometry Center.
It is now supported by volunteers, and commercially support is available from
Geometry Technologies.
Geomview runs well under Linux and other platforms but does not yet have a Windows port.
Geomview makes it easy to add interactive visualization to your own programs.
It takes advantage of the Mesa 3D graphics library,
which taps the capabilities of 3D graphics cards.

The web has been very good to computational geometry.
Netlib
continues to provide access to
triangle, hull, and
sweep.
When you really need a mesh for finite element analysis, you should
check out
Finite element mesh generation
. If you need a really fancy mesh, look in the
Meshing Research Corner. Some of those guys mesh like their lives
depend on it.

When you **need** the Voronoi object, and you have more dimensions than
you should, then you can find relief at the
Home page for Qhull.

I shouldn't be amazed, but I am anyway, by the claims made about
The Ipe extendible drawing editor
. How about editing arbitrary postscript, extensibility,
computing Voronoi diagrams, and clipping to polygons?
After all, we're talking free software that runs on Linux!

It seems like we all live within a world of constraints, and it is
difficult to see what all our possibilities are. Some nice work has
been done on
Geometric Constraint Solving, but they aren't giving away the code.

Now, what if you wanted to glue a mesh generator to Matlab and solve
an isotropic nonconstant-coefficient Laplace equation?

Polygon soups are models which contain no adjacency information and
obey no topological constraints.
RAPID is a
rapid and accurate polygon interference detection library for
large polygon soups.

Since this is supposed to be both fun and educational, maybe you
should just go straight to
David Eppstein's pages, which include
The Geometry Junkyard, one of the most interesting places on the net.

#### 9/2/2001, updated 8/31/2003

By toma