Variable Winds

Hi,

I'd like to be able to represent "variable winds" using the
visad.bom.BarbRendererJ3D and BarbManipulationRendererJ3D classes. I'm
thinking of the following approach:

* the user currently interacts with BMR by right clicking & dragging on
the wind barb. There is no way to indicate a "variable" wind
* I can attach a KeyboardBehaviorJ3D to the DisplayRenderer, modelled on
CBMKeyboardBehaviorJ3D
* I can listen for the "V" key to indicate a variable wind
* I could then set the Wind Direction of the wind barb to, say,
Double.NaN (so far so good)
* then, I'd like to be able to modify BarbRendererJ3D to check for a
wind direction of NaN (with a non-NaN wind speed), and take special
action to indicate a variable winds (eg dashed circle instead of the
continous circle currently done for calm winds)
  _but_ when I look in BarbRendererJ3D, the dir/spd has already been
converted to u & v components somewhere along the line (_and_ are
floats).

So, my questions are:
* is my approach sound, and if so, where should I be looking to define a
"variable wind"
* if not, what are the alternatives.

Thanks in advance for your help,

Cheers,

James
-- 
James Kelly                                          Regional Computing 
Phone: 61-3-9669-4724 Fax: 61-3-9669-4128     Email: J.Kelly@xxxxxxxxxx