2009

■ When a particle hits too near the edge of a face referenced by a UDeflector,
and neither face finds it
■ When a particle is moving quickly and first appears too close to the
deflector, so the very first update cycle within the particle system takes it
past the deflector without the deflector ever seeing it
Often this isn't a problem because the particles bounce off solid objects, so
you don't see the errant particles. When it does cause problems, you can use
a planar deflector instead of a UDeflector, a collection of planars to
approximate the mesh, or a simple mesh to replace the planar. The solutions
vary, so where one has a glitch the other might work just fine.
If particles are moving fast and the deflector is in a particular position (for
example, it might be too close to the emitter) many particles can leak through
defectors. Sometimes you can fix this leakage by changing the particle system's
Subframe Sampling setting or the particle speed. Other times you must
reposition the deflector farther away from the emitter.
In addition, particles imbued with
bubble motion on page 3067 can leak through
deflectors, particularly when set to high amplitudes. To avoid this, use
alternative methods of implementing bubble-like motion, such as varying
speed (see
Particle Generation Rollout on page 3049), setting a higher angle for
the stream spread with spray systems (see
Spray Particle System on page 3016,
Super Spray Particle System on page 3025), or using larger particles with an
animated texture map.
Space Warp Categories
There are four categories of space warps, available via the list on the Create
panel's Space Warps category.
Forces
These space warps are used to affect particle systems and dynamics systems.
All of them can be used with particles, and some can be used with dynamics.
The Supports Objects of Type rollout indications which systems each space
warp supports.
2688 | Chapter 14 Space Warps and Particle Systems