9

238 Chapter 11: Space Warps and Particle Systems
Note:
P articles can participate in dynamics
simulations.
See also
Par ticle System Usage (page 2–238)
Creating a Par ticle Emitter (page 2–239)
Par ticle Flow (page 2–109)
Usi ng Pa rti cl e S y st ems
Youcreateparticlesystemswhenyouwantto
model an object or effect that can best be described
as a large collection of similar objects behaving
inasimilarfashion.Obviousexamplesofsuch
effects include rain and snow, but other equal ly
valid examples include water, smoke, ants, and
even crowds of people.
OntheCreatepanel,clickSpray,Snow,Super
Spray, Blizzard, PArray, or PCloud to create a
particle system. Spray and Snow exist primarily
forcompatibilitywithearlierreleasesof3dsMax,
and are superseded by Super Spray and Blizzard.
To create a particle system, first choose Create
menu > Particles > Spray or Snow.
These are the basic steps for creating a particle
system:
1. Create a par ticle emitter. All particle systems
requireanemitter.Someparticlesystemsuse
theparticlesystemiconastheemitterwhile
others use an object you select from the scene
as the em itter.
2. Determine the number of particles. You set
parameters such as birt h rate and life span to
control how many particles can exist at any
given time.
3. Set particle shape and size. You can select
from many standard particle types (including
metaballs) or you can selec t an object to be
emitted as a particle.
4. Set initial par t icle motion. You can set the
speed, direction, rotation, and randomness of
particlesastheyleavetheemitter.Particlescan
also be affected by animation of the emitter.
5. Modify particle motion. You can further
modify the motion of particles after they leave
the emitter by binding the p a rticle system to a
space warp in the Forces g roup, such as Path
Follow,ormakethembounceoffadeflector
in the Deflectors space warp group, such as
UDeflector.
Impor tant: When you use forces and deflectors
together, always bind the forces before the
deflectors.
Tip:
If the particles don’t follow the emitter
after it’s moved, then change any Path Follow
parameter (page 2–71).Themotionwillbe
applied to the particles.
Rain and Snow
Create rain and snow using Super Spray (page
2–249) and Blizzard (page 2–251).Theseparticle
systems are optimized for droplet (Super Spray)
and tumbling flake (Blizzard) effects. Add space
warp s such a s Wind (page 2–75) to create spring
rains or winter storms.
Bubbles
Create bubbles by using the Bubble Motion
options of Super Spray (page 2–249).Ifyourequire
good rendering speed, consider using constant
or tetra particles. If you require bubble detail,
consider using opacity-mapped facing particles,
instanced spheres, or metaparticles.
Flowi n g Wa ter
You generate flowing liquid effects by setting Super
Spray (page 2–249) to generate closely packed