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686 Chapter 12: Animation
the “fixed” camera parameters to compute the
ones being estimated and simply won’t work if
they’re fixed at incorrect values.
4. You m ay know that some of the camera
parameters don’t vary during a match
sequence, but you aren’t sure of their values.
One approach to this situation is to enable all
parameters for an initial match and then apply a
straight-line average fi lter to them in the Move
Smoothingrollout.Thisautomaticallydisables
them in the Match sec tion and with luck sets
thematagoodestimateofthefixedposition.
Dynamics
Utilities panel > Utilities rollout > More button > Utilities
dialog > Choose Dynamics.
The term dynamics refers to a system of controls
that generate keys to produce animation that
simulates real-world physics. For example, using
standard keyframing techniques to animate a
bouncing ball, you create keys that move the ball
downtothefloor,squashtheball,movetheball
back up, and so on.
Using a dy namics system, you assign physical
properties to the ball and the floor (such as friction
or amount of bounce), specify which object
will collide against another object (for example,
theballwiththefloor),placeaneffect(suchas
gravity),inthescene,andthencalculateasolution
over a range of frames. The result is a number
of keys tha t produce an animation in which the
ball drops due to the gravity effect, collides with
the floor and reacts naturally based on its sur face
characteristics.
Note: As of 3ds Max 5, the preferred tool for
dynamics simulation is rea ctor,availablefrom
the Utilities panel. The reactor plug-in lets you
control and simulate complex physical scenes with
ease. reactor supports f ully integrated rigid and
soft-body dynamics, cloth simulation, and fluid
simulation.
Objects and Space Warps Used to Create
D yna mics Si mula tions
A ver y basic simulat ion would involve creating a
sphere and a gravity space warp, add ing the sphere
toanewsimulation,assigninggravityasaneffect
onthesphereandsolvingthesimulation. The
resultisthatthespherefallsundertheforceof
grav ity.
Yo u c a n u s e dynamics objects (page 1–395),
dynamics space warp deflectors (PDynaFlect (page
2–81), SDy naFlect (page 2–85),andUDynaFlect
(page 2–86)), and space warp forces such as
Gravity (page 2–73) and Wind (page 2–75) to
add complexity to a simulation. You can use a
particle stream from a particle emitter as a force
on an object: the particles can collide with and be
deflectedbytheobject,aswellasmoveit.Youcan
attach special dynamics objects to objects, such
as Spring (page 1–400) to simulate the effects of
aspring.
You can combine effects: Wind, gr avity, a spring
object, collision, particle deflection and collision,
as well as surface properties such as friction, can
all work on an object in a simulation. For a full
understanding of what dynamics can do, explore
this topic and areas of 3ds Max that pertain to
dynamics.
Dynamics-Specific Areas in 3ds Max
The Dynamics Utility (this topic)
The Dynamics Utility is the main control center for
dynamics simulations. You specify which objects
are used in the simulation, what their inter activit y
is with each other and with the effects in the scene.
Thesimulationisthen"solved,"generatingthe
keyframes.