20030611: IDV netCDF questions (again)

Dan -


I wanted to let you know I was going to be showing the IDV as part of a
small 
talk I?m giving to middle and high school teachers who are interested in 
bringing visualization elements into their classroom (NCSA-REVITALISE 
program). The interesting thing about this is that the participants will
have 
their own computers, so they will be able to follow along and work
through 
creating a simple visualization with me. 
One of the things we want to do is take a time step from the storm model
Bob 
Wilhelmson and NCSA rendered for their famous 1989 video and setting it
in the 
IDV. This way, we can show the teachers the video on a TV, and then let
them 
?see? the storm on their own computers using software they can
(hopefully) use 
in their own schools.

- sounds like a good use of the IDV

However, I am running into a couple of issues that most likely someone
with 
more extensive experience in VisAD and IDV can answer. The first is that
the 
data has a horizontal resolution of 1km, which roughly translates to 
.01degrees. When I create an isosurface with this data, it produces
holes, or 
gaps in the surface. When I change the grid resolution to .1 degrees,
the 
holes almost entirely disappear. This is acceptable 

- Have occasionally seen holes in surfaces made from fine resolution
data before.
  I thought they were missing data or NaNs. Don will know more.

 I need to have 
maps turned off, because the storm now covers three states! For this
problem, 
I just want to make sure that the reason the gaps were coming was due to
the 
tight grid spacing, and that there?s nothing else I can do until someone 
addresses this problem.

- So far as I know, yes, the holes occur in surfaces of dense data.

- Why do you turn the map off? Because the data isosurface hides the
map?  You can
  move the map up above the surface with the Maps->Maps Selector -> Maps
position
  menu choice.

The second is one I think you may be able to help me with (provided you
have 
time). I can create isosurfaces and horizontal slices just fine, but I
cannot 
get vertical cross sections to work quite properly.
Here?s what happens. I?m using the IDV updated as of this morning, even
though 
this same problem occurs in earlier WebStart versions.

-  Are you using the "webstart" or new "webstartTest" version? I assume
the webstarttest   version. 

-  Your recent mails says cvs check-ins today helped with the vertical
cross section
  trouble - is there anything else we can answer or do about that?

Stu

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