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1276 Chapter 15: Lights and Cameras
To position a light so it highlights a face:
1.
Make sure the viewport you plan to render is
active, a nd that the object you want to highlight
is visible in it.
The result of Place Highlight depends on what
is visible in the view port.
2. Select a light object.
3. On the Main toolbar, choose Place
Highlight from the Align flyout (page 1–462).
YoucanalsochooseToolsmenu>Place
Highlight.
4. Drag over the object to place the hig h light.
When you place an omni light (page 2–1295),
free point (page 2–1304), free linear (page
2–1307), free area (page 2–1309) or free direct
light (page 2–1293), the program displays a face
normal for the face the mouse indicates.
When you place a target point (page 2–1303),
target area (page 2–1307), target linear (page
2–1305) or target direct light (page 2–1292),the
programdisplaysthelight’stargetandthebase
of its cone.
5. Releasethemousewhenthenormalortarget
display indicates the face you want to highlight.
The light now has a new position and
orientation. You can see the highlight
illumination in shaded viewports that show
thefaceyouchose,andwhenyourenderthose
views.
Place Highlight (page 1–467) works with any
kind of selected object. You can also use Place
Highlight with a selection set of multiple
objects. All objects maintain their initial
distance f rom the face.
Note: For materials, highlig ht rendering
depends on the material’s specular properties
and the type of rendering you use.
Pr oper t ies of L ight
This topic describes lig ht in the real world. When
you light a scene, it can be helpful to know how
light naturally b ehaves.
Whenlightraysstrikeasurface,thesurfacereflects
them, or at least some of them, enabling us to see
the surface. The appearance of a surface depends
on the light that strikes it combined with the
properties of the surface m aterial, such as color,
smoothness, and opacity.
Materials (page 2–1395) let yo u specify the visual
properties of surfaces.
Intens it y
Theintensityoflightatitspointoforiginaffects
how brightly the light illuminates an object. A dim
light cast on a brightly colored object shows only
dim colors.
Left: A room lit by candles, which are a low-intensity source.
Right: The same room lit by a higher-intensity light bulb.
Angle of Incidence
The more a surface inclines away from a light
source, the less light it receives and the darker it
appears.Theangleofthesurfacenormalrelativeto
the light source is known as the angle of incidence.
When the angle of incidence is 0 degrees
(that is, the light source strikes the surface
perp endicularly), the sur face is illuminated with
the full intensity of the light source. As the ang le of