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1282 Chapter 15: Lights and Cameras
and use lights that effect ambient only to simulate
theregionalareasofdiffusereflection.
You set the scene’s ambient li g ht using the
Env i ronment And Effects dialog > Environment
panel (page 3–272).Yousetalighttoaffectonly
ambient illumination with its Advanced Effects
rollout (page 2–1341) >AmbientOnlycheckbox.
Posit ionin g L ight Obj ects
Once you have placed lights in your scene, you
can use transforms to change a lig ht’s position or
orientation.
Transforming Lights
Usetransformsonlightobjectsasfollows:
Move: Use Move (page 1–439) to change the
position of lights. You can also use it to change the
position of light targets.
Rotate: Use Rotate (page 1–439) to change
the orientation of lights.
Note: You can’t rotate a target light about its local X
orYaxes.Instead,useMovetomovethelightor
its target. Rotating the light about its local Z axis
can be useful if the light uses a rect angu lar beam
or projects a bitmap.
Rotating a plain omni light or a photometric
isotropic light has no effect as these lights cast light
uniformly in all directions. However, rotating
an omni or isotropic projector light causes the
projected image to rotate.
Rotating a photometric isotropic light has no effect
as these lights cast light uniformly in all directions.
However, rotating an isotropic projector light
causes the projected image to rotate.
Scale: Scaling Point, Linear, or Area lights
has no effect. Using Scale (page 1–441) with
spotlights and directional lights changes the
size of their l ight beam and attenuation ranges.
Scaling omni lights changes only the attenuation
ranges. Scaling photometric lights changes their
attenuation rate.
Light viewports (page 3–750) are another
convenient way to transform and change
param eters of spotlig hts and directional lights.
Tip: When you adjust lights, it can be usefu l to tur n
on Degradation Override (page 1–34). If O verride
is off and shaded viewports beg in to display in
w ireframe, you c an’t see the result of the changes
you make to lights.
Placing Highlights
Yo u u s e Place Highlight (page 1–467) to position a
light to create a specular highlight at a designated
point on an object. Place Highlight is one of the
buttons on the Align flyout. Place Highligh t moves
or rotates the selected light object to aim it at a
face on an object you pick. The light maintains its
original distance from the face. Place Highlig ht
works w ith any kind of selected object. You
can also use Place Highlight w ith a selection set
that contains more than one object. All objects
maintain their initial dist ance f rom the face.
Animating Lights
You animate lights by using transforms or changing
creation parameters on different keyf r ames while
the Auto Key button (page 3–717) is on. During
animation, light transforms and parameter values
are interpolated between keyframes.
Moving and Rotating Light Objects
You can use the following methods to move and
rotate light objects.