[Gmsh] PLOT3D format

[Matt Gundry]

Hello,

I would like to add PLOT3D file format (ASCII) output capabilities to Gmsh.
For those who don't know, the PLOT3D format is almost universally used with
all the freely available CFD goodies from NASA. The format stores structured
meshes and is fairly simple. The following site describes the format:

http://www.grc.nasa.gov/WWW/wind/valid/plot3d.html

Basically, I first need to output the grid i j k dimensions. Then I list the
X coords for each node in order (for k (for j (for i))), Y coords, then Z
coords.

I've briefly examined the source for the output translators that come with
Gmsh, and I guess my biggest question is what is the best way to get the
grid dimensions and node coordinates in order. Put another way, I can see
how to get the coordinates for each node of each face, but I was hoping for
some assurance that the order of faces in a structured grid is consistent.

Knowing that, I think this will be pretty simple.

Thanks,
Matt