9

Area Shadows Rollout 1357
batchofraysiscasttofurtherrefinetheedge.
The number of initial rays is specified using
the Pass 1 Quality spinner. The number of
secondaryraysisspecifiedusingthePass2
Quality spinner.
2-Sided Sha dows—When on, backfaces are not
ignored when calculating shadows. Objects seen
fromtheinsidearenotlitbylightsfromthe
outside. This costs a bit more render time. When
off,backfacesareignored.Renderingisquicker,
but outside lights illuminate object interiors.
The faces inside the sliced sphere do not cast shadows if 2-Sided
Shadowsisnotselected.
Antialiasing Options group
Shadow Integrity—The number of rays cast f rom
an illuminated surface.
Shadow Quality—The number of secondar y rays
cast from an il luminated surface.
Shadow Spread—The radius, in pixels, to blur the
antialiased edge.
Note: As this value increases, so does the quality
of the blur. However, increasing this value also
increases the likelihood of missing smal l objects.
To avoid this problem, increase the value of Pass 1
Quality.
Increasing the Shadow Spread value softens shadow edges.
Shadow Bias—The minimum distance from the
point b eing shaded that an object must be to cast
a shadow. This prevents blurred shadows from
affectingsurfacestheyshouldn’t.
Note: As you increase the blur v alue, you should
also increase the bias.
Jitter Amount—Adds randomness to the ray
positions. The rays are initially in a ver y regular
pattern, which can show up in the blur ry p art
of the shadow as regular artifacts. Jittering w i l l
convert these artifacts to noise, which is generally
less noticeable to the eye. Recommended va lues
are 0.25 to 1.0. However, very blurry shadows will
requiremorejitter.
Area Shadows R ollout
Create panel > Lights > Create or select a light. > General
Parameters rollout > Shadow type > Area Shadows rollo ut
The Area Shadow generator can be applied to any
lighttypetoachievetheeffectofanareashadow
effect. In order to create an area shadow, the user
needs to specify the dimensions of a vir tua l light
created to "fake" an area shadow.
Note: When using a rea lights, the user should
try to make the properties of the light m atch the