8

Isotropic Light D istribution (Photometric Lights) 1167
This is useful for doing night shots with artificial
lighting.
Sky Col or—The color swatch opens the
Color
Selector (page 1–157)
,whichletsyousetthecolor
of the sky.
Coverage group
Cle ar, Pa rt ly Cloud y, Clou dyThis choice
determines how much light is scattered through
the sky.
Render group
Cast Shadows—Causes the sky lig ht to cast
shadows.
A great deal of processing is dedicated to the
calculation of the subtle shadows cast by
skylight
(page 3–1106)
.Ifshadowsarenotimportant
in your model, you can disable them and save
substantial amounts of processing t ime. However,
the results will not be as realist ic.
Note: TheCastShadowstogglehasnoeffectwhen
using radiosity or the light tracer.
Note: IES Sky objects will
not
cast shadows in an
ActiveShade rendering (page 3–17)
.
R ay s per Sample—The number of rays used to
calculateskylightfallingonagivenpointinthe
scene. For animation you should set this to a high
value to eliminate flickering. A value of around 30
should eliminate flickering.
Increasing the number of rays increases the quality of your
image. However, it also increases rende ring time.
Ray BiasThe closest distance at w hich objects
can cast shadows on a given point in the scene.
Settingthisvalueto0cancausethepointtocast
shadows upon itself, and setting it to a large value
canpreventobjectsclosetoapointfromcasting
shadows on the point.
Is otropi c Light Di str i bution
(Photometr ic Lights)
Create panel > Lights > Photometric Lights > Click Target
Point or Free Point. > Intensity/Color/Distribution rollout
> C hoose Isotropic in Distribution list. > Click in viewport
to create light.
An Isotropic light distributes the light equally in
all directions.
Isotropic light distribution
Icon for Target Point light with isotropic distribution
See also
Lights (page 2–1126)
Target Point Light (Photometric) (page 2–1157)
Free Point Light (Photometric) (p age 2–1158)