With this methodology, you could bake out the animation of any simulation, from
dynamics (as we just did) to constraints and some scripts. The curve simplification works
with good old-fashioned keyframed curves as well, so if you inherit a scene from another
animator and need to simplify the curves, do it just as we did here.
Like rigid body objects, particles are moved dynamically using collisions and fields. In
short, a particle is a point in space that is given renderable properties; that is, it can render
out. When particles are used en masse, they can create effects such as smoke, a swarm of
insects, fireworks, and so on. Although particles can be an advanced and involved aspect
of Maya, it is important to have some exposure to them as you begin to learn Maya.
Much of what you learned about rigid body dynamics transfers to particles. However, it
is important to think of particle animation as manipulating a larger system rather than as
controlling every single particle in the simulation. You control fields and dynamic attrib-
utes to govern the motion of the system as a whole.
For example, with the pool table you control the motion of the cue ball and let Maya
dynamics calculate the motion of the other balls after they collide. Each ball is a distinct
part of the scene and renders out as a distinct object in the frame. Particles are most often
used together in large numbers so that the entirety is rendered out to create an effect. To
control a particle system, you’ll create an emitter and define fields and attributes that con-
trol the particles’ movement.
Creation options for
a Particle emitter
Typical work flow for creating a particle
effect in Maya breaks into two parts: motion
and rendering. First, you create and define
the behavior of particles through emission.
An emitter is a Maya object that creates the
particles themselves. After creating fields
and adjusting particle behavior within a
dynamic simulation, much as you would do
with rigid body motion, you give the parti-
cles renderable qualities to define how they
look. This second aspect of the workflow
defines how the particles “come together” to
create the desired effect, such as steam. You
will make a steaming locomotive pump later
in this chapter.
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