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182 Chapter 11: Space Warps and Particle Systems
Particles falling onto a two-element cylinder
Left: Allow Multiple Elements is off; Right: Allow Multip le
Elements is on.
Continuous Update—When on, the shape of the
mark is recalculated at each fr ame, according to
the current positions of the part icle and the contac t
surface. This option can consume a great deal o f
CPU time. Available only with Box Intersection.
Generate Mapping Coords.—Allows correct
application of the shape mark when using a
mapped material. Default=on.
If you’re not using a mapped material, you can
savememorybyturningthisoff.
Pivot Offset % —Shifts the position of t he shape
mark along its length dimension with respect to
the pivot of the impacting particle. Default=0.0.
Range=-50.0 to 50.0.
By default, the center of the mark’s length
dimension coincides with the point where the
particle’s pivot strikes the contact object. This
setting lets you offset the mark’s position to
anywhere along its length.
Note: T he width dimension and the Box
Intersection’s height dimension are always
centered at the intersection of the particle pivot
and the contact object’s surface.
Surf ace Offset—Specifies the distance of the
shapemarkabovethecontactobject’ssurface.
Default=0.001.
The mark is slightly elevated above the contact
geometry to achieve t he visual effect of the mark
spot overlapping the contact geometry. This
parameter is not animatable.
Offset Variation—Specifies the maximum extent
of a random variation in the actual surface offset
among par ticles. D efault=0.0.
Adjusting this value can help to a lleviate rendering
artifacts with overlapping marks.
Ver tex Jitter—Specifies the maximum extent of a
randomvariationinthepositionsofverticesof
marks created using the Box Intersection method.
Available only with the Box Intersection method.
Default=0.0.
Adjusting this value can help to a lleviate rendering
artifacts with overlapping marks.
Uniqueness group
The Uniqueness setting enables changing the
randomization of the size/width variation.
Seed—Specifies a randomization value.
New—Calculates a new seed using a randomization
formula.
Material and Mapping
Ov er v iew of Ma teri al s in Par ti cle
View
Particle Flow provides three operators for
applyingmaterialstoparticles. Togivethe
same appearance to all particles throughout an
event, use
Material Static Operator (page 2–183) .
If y o u’re using a com pound material such as
Multi/Sub-Object (page 2–1403) , you can assign
different sub-materials to different particles with
the
Material Frequency operator (page 2–185) .
And to assign materials that change in appearance
over time, use the
Material Dynamic operator
(page 2–187)
.