You're welcome. Here are a few answers:
1. Rendering is done in 3d coordinates that you specify (i.e., derived
from your data). Ordering or precedence is based upon the camera view and
the location of the objects in the scene. If you have coincident objects,
precedence can be specified via fuzz. For example, you have a map and a
colored field on the same surface. You want the map to be overlayed on
top. The do the following:
object1 (e.g., map) object2 (e.g., colored field)
| |
Options(,fuzz,4) Options(,fuzz,2)
||
Collect
|
Image
2. Well, ease will have to be from your perspective. There's no built-in
interface although a few DX users have developed custom interfaces. The
easiest is to do a query and dump a table which DX could read via general
array import or ImportSpreadsheet. This could be integrated into DX by
having the query parameterized with the parameters exposed as widgets in
the UI. The inputs are then assembled into a query, which could be run as
a script or program by the Import module (! in front of a file name tells
DX to execute whatever the file is instead of reading it). That script
passes the query to Oracle, the results come back, the script parses them
and puts them into a form DX can Import. The integration can be better
with more effort where you might write custom modules to interact with
Oracle or have a master program that runs both DX and talks to Oracle, etc.
3. This may be a feature in your data or how your defined it to DX. DX
understands the difference between data defined at grid points or vertices
(e.g., dep positions) and data defined at cell centers (e.g., dep
connections). The former would be typical for data from a simulation
(e.g., from finite difference calculations) while the latter would be
typical for an image, DEM, finite element grid, etc. Unfortunately, many
data formats and visualization tools, particularly in atmospheric and space
sciences ignore this distinction, which can be a real problem. So, your
data may have global coverage but is defined to DX as dep positions,
implying the data are at vertices. For example, consider a global
cartesian grid at one degree resolution (e.g., 360x180). If you define the
data at vertices of the quads every degree, then you will have the gap that
you describe. If the data are defined at intermediate locations (e.g., at
half degree intervals) then the gap may be smaller but misregistered. If
the data are defined at cell centers, then there's no gap. You could use
Slab to extract a column and then CollectMultiGrid to add it to the end
of the grid, but this could be wrong as far as the data are concerned. You
really need to find out what the data are actually defined and then tell DX
so it does the right thing.
4. Open it directly in the VPE or place the macro in your main program,
select and the use the pulldown in the VPE to open it.
Paul Skeie [EMAIL PROTECTED]@opendx.watson.ibm.com on 12/14/2000
07:09:51 AM
Please respond to opendx2-users@lists.berlios.de
Sent by: [EMAIL PROTECTED]
To: opendx users opendx2-users@lists.berlios.de
cc:
Subject: [opendx-users] How control layers?
First I want to thank L.A. Treinish for a very helpful reply
to my first submittance to this list.
Then to some new questions:
1.
How can I control the order in which visual objects
are rendered to an image? What decides the order if nothing is specified?
2.
Can I easily make DX communicate directly with an Oracle database?
3.
When I display data that are on a global geographical grid I get
a sectorial hole in the plot near the dateline (origo). I guess I could
avoid this by copying the leftmost column of my datamatrix (data at 180W)
to a new column on the right of the datamatrix. I could do this on the
datafile,
but this would take up diskspace and is not a very elegant solution. Could
someone suggest another workaround? Can I use the Compute module?
4.
How do I edit an existing macro?
I know these questions may seem silly to experts so please, be patient
with me.
Cheers,
Paul Skeie
