Graphics Reference
In-Depth Information
In 3D, there are a number of different light styles, each with their own set of properties and effects.
Blender's Spot Lamp, for example, can cast the kind of “light cone” that many people expect to see in
concert or film noir situations. While real-world shadows are simply a consequence of the physics of light,
3D shadows can be turned on or off and have several calculation methods, each of which is appropriate
to a different situation.
More than any other aspect of the 3D creation process, effective lighting will require that you carefully
consider the 2D images you want to generate. Beyond just showing the forms in a picture and their sur-
facing, lighting sets a mood, directs the eye, becomes a part of the composition, and will either make or
break your final image.
Motion
In the real world, things move. We're accustomed to the way that things move, and when we see unnatural
motion we know it right away. It looks bad. As 3D artists we are not trying to recreate the world. What
artistry or skill would there be in a painstakingly exact reproduction of real motion, other than technical
curiosity? What purpose would it serve?
Fortunately, this is ground on which lies a well-worn path. Since its beginning in the 1920s, artists and
entertainers have a developed a well-known language for animation. Things that would look bizarre in the
real world—bulging eyes, rubbery arms, and the ability to hover for a moment before falling off a cliff—
are perfectly acceptable and actually expected by the viewer in the realm of animation.
Whether for film, television, or even content produced exclusively for viewing on the Internet, animation
works the same way. It is a series of still images shown rapidly one after the other, producing the illusion
of actual motion. In traditional (hand-drawn) animation, each of those frames must be drawn individually.
At 30 frames per second (the frame rate of North American television), that's 900 images for just 30 seconds
of animation. In other words, it is a lot of drawing.
Computer animation, which is what we're about, is in some ways easier. If you were to follow the tra-
ditional model of animation, you would create the entire scene 900 times, each with a slight variation.
Obviously, that's silly. Within your single scene you have the ability to record and change objects' posi-
tions (e.g., on the floor, in the air), states (e.g., lights on, lights off), and poses (e.g., reaching for a towel,
pulling on a shoe) along a timeline, and have the software calculate all of the positions, states, and poses
in between. The process of saving this information in time is called
keyframing
(“key” information is saved
on certain “frames” in the timeline;
Figure 1.9
).
In Blender, keyframes are created for entire objects by transforming them in space and recording their
status. When you add several keyframes, Blender interpolates the difference between them along smooth
curves. Character models are not animated directly. Instead, they are attached to control rigs called arma-
tures. These rigs act like a skeleton and control panel that can be posed and keyframed to produce beautiful
character animation.
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