Cumulonimbus Clouds in WorldBuilder: Page 2
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A
sub-property of Cloud Shape is Cloud Profile.
This is a graphical interface for editing your cloud' s
profile, represented here as a spline curve with movable
points. Click and drag on the points to alter the
cloud' s shape.
Double-click
to add a new point to the profile curve; right-click to
delete a point. Try out a few combinations to see
what kinds of cloud shapes you can make.
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Here
are some rendered examples.
Now
that we' ve made some adjustments to the shape of our
cloud, let' s explore our shading options. In the
Properties Tree, select Cloud Shader.
First
in the Cloud Shader property is Extinction. Use
this to control the cloud' s transparency. A high
setting will make the cloud very solid and opaque, while a low
setting will make the cloud more wispy and ‘fog-like' .
The
practical range for this control is roughly between 1
(almost completely transparent) to 10 (above which
increasing opacity values are not as noticeable); a good starting
value is the default setting of 3.
Let' s
render a couple of different Extinction settings.
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Extinction
= 1.25 |
Extinction
= 2 |
Extinction
= 6 |
The
Intensity parameter controls the cloud' s responsiveness
to a light source. Low settings cause the cloud to render
very dim and very flat; a high setting will cause the directly illuminated
areas of the cloud to become so bright that shadowed areas of the
cloud will be obscured.
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Intensity
= 2.5 |
Intensity
= 10 |
Intensity
= 20 |
The Asymmetry parameter controls the scattering of light within
the cloud' s volume. A low setting (0.1 or lower)
will cause the light to scatter ‘isotropically' (equally
in all directions) within the cloud, which will appear darker; a higher
setting will cause the light to scatter in a more uniform direction,
creating brighter areas within the cloud.
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Asymmetry
= -0.8 |
Asymmetry
= -0.1 |
Asymmetry
= 0.4 |
Albedo
controls the overall contrast between the brighter, directly illuminated
areas of the cloud and the darker shadowed areas.
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Albedo
= 0.23 |
Albedo
= 0.45 |
Albedo
= 1.8 |
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