Apple Motion 5.1.1 User Manual
Page 538
 
Chapter 14
Particles
538
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Life Randomness: A slider that defines an amount of variance in the life of generated particles. 
A value of 0 results in no variance—all particles from the selected cell emerge with the same 
lifetime. A value greater than 0 introduces a variance defined by the Life parameter, plus or 
minus a random value falling within the Life Randomness setting.
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Speed: A slider that defines initial speed. This parameter determines how quickly each particle 
flies away from the emitter. This, in conjunction with the Life and Birth Rate parameters, 
determines how many particles appear in the Canvas at a given frame. It is equivalent to one 
of the functions of the graphical emission control in the HUD.
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Speed Randomness: A slider that defines an amount of variance in the speed of generated 
particles. A value of 0 results in no variance—all particles from the selected cell emerge with 
the same speed. A value greater than 0 introduces a variance defined by the Speed parameter, 
plus or minus a predetermined random value falling within the Speed Randomness setting.
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Align Angle: When this checkbox is selected, particles rotate to match the shape on which 
they are positioned. This parameter is available in all cases but the following: when the 
Shape setting (in the Emitter Inspector) is Rectangle, Circle, Image, Box, and Sphere and the 
Arrangement setting is with Tile Fill or Random Fill; or when the Shape setting is Point.
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Angle: A dial that defines the angle of rotation, in degrees, at which new particles are created.
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Angle Randomness: A dial that defines an amount of variance in the angle of 
generated particles.
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Spin: A dial that animates particles in a system by initially spinning each particle around its 
center. Adjustments to this control are in degrees per second.
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Spin Randomness: A dial that defines an amount of variance in the spin of generated particles. 
A value of 0 results in no variance—all particles from the selected cell spin at the same rate. 
A value greater than 0 introduces a variance defined by the Spin parameter, plus or minus a 
random value falling within the Spin Randomness setting.
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Additive Blend: By default, particles are composited together using the Normal blend mode. 
Select this checkbox to composite all overlapping generated particles together using the 
Additive blending mode. This blending occurs in addition to whichever compositing method 
is already in use. The result is that the brightness of overlapping objects is intensified. This 
effect applies to the particle system itself—the blend mode of the emitter determines how the 
result of the emitter is blended into the scene.
Additive Blend off
Additive Blend on
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