2009
Horizon group
Height The vertical position of the horizon. Default=0.0.
For details, see
Horizon Height on page 5172.
Blur The “blurriness” with which the horizon is rendered. Default=0.1.
At 0.0 the horizon is completely sharp. Generally only values lower than 0.5
are useful, but the full range is up to 10.0 for a horizon that consists of blur
only, with no actual horizon at all.
Night Color
Night Color The minimum color of the sky: the sky will never become darker
than this value. This adjustment can be useful for adding things like the moon,
stars, high-altitude cirrus clouds that remain lit long after sunset, and so on.
As the sun sets and the sky darkens, the contribution from Night Color is
unaffected and remains as the base light level.
Non-Physical Tuning group
Red/Blue Tint Provides artistic control over the redness of the sky light. The
default value of 0.0 is the physically correct value (calculated for a 6500K
whitepoint), but can be changed with this parameter, which ranges from –1.0
(extremely blue) to 1.0 (extremely red).
Saturation Provides artistic control over saturation of the sky light. The default
value of 1.0 is the physically calculated saturation level. Possible values range
from 0.0 (black and white) to 2.0 (extremely high saturation).
Aerial Perspective group
Aerial Perspective toggle When on, enables the Visibility Distance setting.
When off, disables the effect of Visibility Distance. Default=on.
Visibility Distance Aerial Perspective is a term used by painters to convey
how distant objects are perceived as hazier and tinted towards the blue end
of the spectrum. mr Sky emulates this with the Visibilty Distance parameter.
When nonzero, it defines the “10% distance”, that is, the distance at which
approximately 10% of haze is visible at a Haze level of 0.0.
5178 | Chapter 18 Lights and Cameras