Graphics Reference
In-Depth Information
Point lamps are good for
subtly brightening areas that
do not receive enough light
due to shadows and lamp dis-
tance. Remember that areas
that fall within shadows will
not be receiving bounced
light from other sources.
Sun Lamp
Figure 5.5
shows the control
panel for working with sun
lamps, beside its representation
in the 3D view. Unlike a point
lamp, the actual location of the
sun lamp in a scene doesn't
matter, only the orientation.
The sun lamp has a dashed line
extending below it. This line
indicates the direction in
which the “sun” is pointing.
You change the orientation of
this line with the R key, as a
standard object rotation.
When a sun lamp is added to a scene, it provides uniform illumination in a single direction. With the Ray
Shadow option enabled, this is easy to see, as all of the shadows in the scene are parallel. Shadows from
lamps that are location-dependent always diverge. You can see the difference in
Figure 5.6
.
Because the location of the sun lamp is not taken into account, there is no Distance control.
Sun lamps are good for outdoor lighting, to mimic the very distant sun.
Figure 5.5
The sun lamp control panel.
Hemi Lamp
Figure 5.7
shows the hemi lamp in the 3D view, with its accompanying control panel. Like the sun lamp,
they are not location-dependent. Only their orientation matters. Hemi lamps come with only two controls:
Energy and Color.
The purpose of a hemi lamp is to provide a controllable, directable level of overall lighting. There will be
many situations in which, due to shadowing, there are areas of your scene that don't receive direct light.
One of the ways to prevent those areas from appearing completely black is to use one or more hemi lamps.
Here's how they work: Hemi lamps provide illumination on each object in a scene as though they were
individually surrounded by a large glowing hemisphere (like the sky), with its open end facing in the
direction of the lamp. While it would be great to just assign a light-blue hemi lamp pointing straight down
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