Adobe atmosphere builder 1 Manuale Utente

Pagina di 84
56
Adding Lighting
3
In the Object Inspector palette, specify values for Red, Green, and Blue by dragging the 
color sliders or by entering numbers.
4
Click the sky to apply the color. 
To apply a color or texture to a hidden luminous surface:
1
In Browser view, select the move tool 
(
)
, and select Show Hidden Objects in the Tool 
Inspector palette.
2
Navigate until you can see the hidden luminous surface, and apply a color or texture to 
Lighting a world
When you light a world for the first time, Atmosphere Builder calculates all of the 
distributed light in the world. How much light each non-luminous surface receives is 
based on its spacial relationship to luminous surfaces in the world. Non-luminous 
surfaces that are close to a luminous surface receive more light than those that are far away 
from a luminous surface. Lighting is assigned to surfaces using a light map. A light map is 
an RGB image of the lighting value for each unit of surface area in a world. This light map 
is imposed over the world’s surface textures to create the appearance of light and shadows.
With each subsequent lighting pass, Atmosphere Builder recalculates the distributed light 
in the world. Surfaces that were previously unlit now reflect light—this reflected light, in 
turn, goes on to illuminate other surfaces in the world. To understand how Atmosphere 
Builder uses the principle of reflected light, imagine a room with one red wall, one green 
wall, and a white light in the center of the ceiling. During the first lighting pass, the red 
wall and the green wall are illuminated by the white light. During the second lighting pass, 
the light that is reflected by both walls is added to the distributed light in the world. The 
red wall receives green light and vice versa. Because of this, the lighting in the world 
becomes more subtle with each lighting pass.
Using the Lighting Control palette
The Lighting Control palette contains options for lighting a world. It also displays the 
number of faces that remain to be processed during a lighting pass and the percentage of 
pixels left to light in the currently-processing face.
atmosphere.book  Page 56  Wednesday, March 21, 2001  6:14 PM