Getting Started
with VNS 3: Fields
& Forest
Part 5D. Global Ecosystems
1. We're going to create a simplified
global Environment with 2 Ecosystems; Grassland for the
canyon floor and Pine Burn for everywhere else. The Pine
Burn Ecosystem will include young lodgepole pine and bleached
snags, regrowth after fires that swept through the area.
2. If you haven't done so already,
go to the Window menu and Close All windows to
clear our workspace. Go to the Land Cover Task mode. Select the Ecosystem category and
Add Component from Gallery.
3. Load the Grassland
Ecosystem.
4. It doesn't matter how you
answer the scaling question; we'll be changing the Elevation
Line anyway.
5. Expand the Ecosystems
and Environments categories and add the Grassland
Ecosystem to the YNP Environment. Confirm the operation
and save the project.
6. Go to the Ecosystem Editor Rules page to see where Grassland
will render. Just about everywhere, it seems. The upper Elevation
Line is 10 kilometers and the slope range is 0-90°.
7. Turn to the Material page.
There's only one Material, Grassland, with a Diffuse Color
texture and Understory.
8. The Foliage page shows
the Grassland Ecotype properties.
9. The Ecotype has Foliage
Objects that will slow rendering, so select the Understory category
and disable it for now.
10. Go back to the Rules
page. With the Diagnostic
Data tab visible, click and drag around the valley
floor margin in the YNP Main view. The elevation is about
2060 meters. To include higher valley elevations up the canyon,
enter 2200 meters into the Elevation Line field.
This will restrict the Grassland Ecosystem to elevations below
2200 meters.
11. Save the project and render
a preview. You can see the upper limit of the Grassland Ecosystem
on the far cliffs.
12. With the Ground Effect,
we used a Material Gradient slope range of 18-27°
to transition from Flat to Steep Materials. Enter
a Maximum Slope of 27° to achieve a similar
effect with the Grassland Ecosystem. This will soften the elevation
transition and restrict the Grassland to gentler slopes beneath
the Elevation Line.
13. Save the project and render
a preview. If you haven't done so already, visit the Interactive Reference
Manual and read more
about how the Rules-of-Nature can be used to control Ecosystem
rendering and mimic nature.
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