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1130 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, and that the object you want to hig hlight
is visible in it.
The result of Place Hig hlight 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 1–446) .
YoucanalsochooseToolsmenu>Place
Highlight.
4. Drag over the object to place the highlig ht.
When you place an
omni light (page 2–1148) ,
free point (page 2–1158) , free linear (page
2–1160)
, free area (p age 2–1162) or free direct
light (page 2–1147)
, the program displays a face
normal for the face the mouse indicates.
When y o u place a
target point (page 2–1157) ,
target area (page 2–1161) , target linear (page
2–1159)
or target direct light (page 2–1145) ,
the program displays the light’s target and the
base of its cone.
5. Releasethemousewhenthenormalortarget
display indicates the face you want to highlight.
The lig ht now has a new position and
orientation. You can see the highlight
illumination in shaded viewports that show
thefaceyouchose,andwhenyourenderthose
views.
Place Highlight (page 1–452) works with
anykindofselectedobject. Youcanalsouse
Place Highlight w ith a selection set of multiple
objects. All objects maintain their initial
distance f rom the face.
Note: For materia ls, highlight rendering
depends on the material’s specular properties
and the type of rendering you use.
Pr oper t ies of Li ght
This topic describes light in the real world. When
you light a scene, it can be helpful to know how
light naturally behaves.
Whenlightraysstrikeasurface,thesurfacereflects
them, or at l east 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 material, such as color,
smoothness, and opacity.
Materials (page 2–1239) let you 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 sam e room lit by a higher-intensi ty light bulb.
Angle of Incidence
The more a surface inclines away from a light
source, the less lig ht it receives and the darker it
appears.Theangleofthesurfacenormalrelativeto
the l ight source is know n as the
angle of incidence .
When the angle of incidence is 0 degrees
(that is, the light source strikes the surface
perp endicularly), the surface is il luminated with
the f ull intensity of the light source. As the angle of