Getting Started
with WCS 6 Part 3B.
Terrain Basics
15. This will launch the now
familiar Import
Wizard, which will correctly
identify the files as SDTS DEMs.
16. Click Next to the
LOAD AS window, accept the defaults.
17. Continue to OUTPUT FILE TYPE
AND NAME. Change the name to YNP-10m, for 10 meters, and
Import.
18. The Status window
will tell you what's going on as the data is imported.
19. After data import is complete,
save the project, and go to the Render Task Mode. Open
the YNP Camera.
20. Name it Main.
21. Use the Edit Next Object
 button to go to
the YNP Planimetric camera and rename it Plan.
22. Open the Main view,
Plan view, and the Database Editor.
23. Activate the Main
camera and Crtl-click to place it in this drainage.
24. Give it an elevation of
2100 meters.
25. Render a preview.
26. Depending on your RAM, one
of 2 things will happen. WCS will either start rendering and
take a long time or give you a Memory Allocation Failure error.
27. To save time, WCS only renders
the DEMs it has to. In this project so far, our Main camera
is only seeing a part of the total terrain. Since we only have
1 DEM, it has to calculate the entire DEM, which is a big waste
of time and memory. The solution? Tile the DEM, that is, divide
it into several smaller DEMs which will mean fewer calculations
and faster render times.
28. Open the Import Wizard, which you can launch from its button 
on the icon toolbar or Crtl+I keyboard shortcut. Choose
the YNP-10m.elev we just created and Open it.
29. Next your way through
the Import
Wizard to the fourth
window, DATA POSITIONING. Previously, this is where we have accepted
defaults and imported. We could do this now and the DEM would
be tiled, but we'd like to see what the Wizard is doing. Select
Change Settings.
30. Click Next five times
to the OUTPUT DEMS page. The information box at the top explains
tiling, telling us the render engine has to load an entire DEM
into memory if any portion of the DEM is in camera view. The
Import
Wizard chooses DEMs Row-Wise
and Column-Wise to divide the imported DEM into 300 row by 300
column tiles. That's where the 7 and 10 come from. We're not
going to change anything so click Import.
31. If you click an Object
in the Database to refresh the list, you'll notice that we now
have 71 objects. That's 70 tiled DEMs, 10 rows times 7 columns,
plus the original DEM.
32. Go to the bottom of the list
and select the original YNP-10m DEM. It's still active,
so if we don't disable or remove it from the Database, it will
still render. Click the Remove button.
33. A question box will pop up
asking if you want to remove the DEM from disk, too. We might
want that DEM later on, so answer No and save the project.
34. Let's try the Main
camera preview render once again.
35. Aside from going much faster,
you'll see from the Status window that we're only rendering
about 20 of our 70 DEMs. This also frees up valuable RAM for
other RAM intensive operations, which we'll need later on.
36. Let's group the 10-meter
DEMs on a layer for easy selection. Click and drag to select
all the objects or select the first one and Shift-click the last
one. The title bar should show all 70 of 70 objects selected.
37. Go to the Layer page
and you'll see TOP, which is the default layer WCS adds DEMs
to.
38. Click Add and enter
10m into the Input Request box for the Layer Name.
This will add all the 10-meter DEMs to a layer named 10m.
39. To test this, select any
object in the list, select the 10m layer, and Select
to select all objects on that layer. This may not seem like much
help now, but it will be when you have hundreds of database objects.
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