So.
I have to style a few layers inside my Weather Research and Forecasting
(WRF) output as either contours or wind barbs. Using the Geoserver/WCS.
We're dealing with the multidimensionality of the dataset by interpolating
the WRF grid to the standard meterological levels and creating one layer
per level (e.g., one Geotiff per variable per vertical level).
For contours, I can make a separate program which generates a contour
feature from a GridCoverage. This can be uploaded to the WFS and treated
like any other layer.
Wind barbs are a problem, however. Examining the SLD spec, I see no
vocabulary for specifying the direction and magnitude attributes (not
geometries) of a layer. My current stab at the problem will be to try and
build a wind barb renderer out of some of Martin's code in "migrate", make
it a "NamedStyle" which requires the feature have U and V attributes, and
figure out how to add this new style to my local Geoserver.
However, this is a new area for me. Should I just make Martin's code in
Geotools' "module/migrate" work with 2.1.0 released jars? Should I make
them conform to GO-1 interfaces? I don't suppose anyone has some sage
words of wisdom for me? Is there an obvious way to do "wind barbs" which I
am just plain missing?
The root problem, of course, is that the SLD spec is written such that
Rasters Shall be Displayed as Pictures, thus alienating the entire
meterological community. 
It would be way awesome if, after I add the
ability to style with wind barbs, I could just style the raster directly
instead of making an intermediate feature. Oh well. Until then I'll hack
away.
Bryce