Sprite attributes

Sprite Animation

Specifies how images are assigned to the sprites. Select one of the following:

Sprite Start Option

Selects the technique used to assign the initial sprite to each particle. Select one of the following:

first: Every particle uses the first image in the sequence.
particleid: The particle uses its particleId value to pick an image. If the particleId is greater than the number of images in the sequence, it starts over with the first image.
random: Each particle uses a random image from the sequence.
custom: The particle uses its spriteNumPP value to select the image. You must set the spriteNumPP values by editing the particle creation expression. See Customizing sprites with the Sprite Wizard.
ramp: Connects a ramp to the spriteNumRamp attribute of the particle object. The ramp determines the image selection. You can modify this ramp to determine which sprite receives each image.

Sprite Cycle Pattern

Specifies how the images are cycled for each particle. Select one of the following:

linearUp: Plays through the image sequence at an even speed.
easeUp: Eases in and eases out the rate that the image sequence is played. The first and last images in the sequence will be used for longer times.
linearUpDown: Plays through the image sequence at an even speed. When the end of the sequence is reached, it plays in reverse.
easeUpDown: Eases in and eases out the rate that the image sequence is played. When the end of the sequence is reached, it plays in reverse.
custom: The particle uses its spriteNumPP value to select the image. You must set the spriteNumPP values by editing the particle runtime expression. See Customizing sprites with the Sprite Wizard.
ramp: Connects a ramp to the spriteNumRamp attribute of the particle object. The ramp determines the image selection. You can modify this ramp to determine which sprite receives each image.

Sprite Cycle Length: Controls the length of each animation cycle. this is valid only if the Cycle only once during lifespan option is disabled.
Sprite Invert Cycle: Invert the meaning of the ramp’s values. Higher values use images closer to the start of the sequence.

Predefined Attributes

The predefined vector array attributes are listed below:

Attribute	To add this attribute:
rgbPP (color)	See Set particle color.
rampPosition, rampVelocity, or rampAcceleration	No action necessary. A particle object has these attributes by default.
goalOffset	See Create goals and Add dynamic attributes.

Attribute	To add this attribute:
opacityPP (opacity)	See Set particle opacity.
radiusPP (radius of Blobby Surfaces, Clouds, or Spheres)	See Add dynamic attributes.
emitterNameRatePP (emission rate of a point emitter)	See Vary emission from different points of point emitters.
goalPP (goal weight)	See Set goal weights on a per-particle basis.
goalU and goalV (NURBS U and V position for goals)	See Add dynamic attributes.
mass	No action necessary. A particle object has this attribute by default.
spriteNumPP, spriteScaleXPP, spriteScaleYPP, and spriteTwistPP (filename extension, X-axis image scale, Y-axis image scale, and image rotation angle of Sprites)	See Add dynamic attributes.
traceDepthPP (collision detection sensitivity)	See Add dynamic attributes.

None: No attribute affects the ramp component. This is the default setting for Input U.
Particle's Age: The particle object’s ageNormalized attribute. This attribute contains the particle’s age, normalized to values between 0 and 1 from birth to death. This is the default setting for Input V.

Note
Maya normalizes only the particle’s age (ageNormalized) values from 0 to 1. All other attributes control the ramp component with their literal values. If the attribute exceeds the range 0 to 1, the values in the ramp repeat. For example, a value of 1.5 represents the same position in the ramp as a value of 0.5.
attributeUPP or attributeVPP: Creates a custom attribute that controls the ramp component. The attribute is named attributeUPP or attributeVPP, where attribute is the name of the attribute that appears in the menu. You can set this attribute with an expression, ramp, or the Component Editor.

Note that you can also select attributeUPP or attributeVPP from the Attribute Editor. Simply right-click the attribute box of the per particle attribute that’s connected to a ramp, slide the pointer to the arrow to the right, and select attributeUorVPP > arrayMapper2.outValuePP.
Other attributes: The Input U and Input V menus also lists all float array attributes in the particle object. You can select one of the listed attributes to control the ramp component.

Break Connection: Breaks the array mapper’s input to the particle shape. This menu item doesn’t delete the ramp node or array mapper. Use this menu item if you don’t want to remove the ramp when you break the connection.
Delete Array Mapper: Breaks the array mapper’s input to the particle shape by deleting the array mapper. The ramp will also be deleted if it has no other connections. Use this menu item if you no longer need the ramp in the scene.

Max Count: Sets a limit on the number of particles the emitted particle object accepts from an emitter.

For example, if you set Max Count to 20, the particle object accepts new particles until it has 20 particles, then the emission turns off. If particles die and reduce the count below 20, more particles emit until the count reaches 20.

The default value of -1 means there is no limit.
Level Of Detail: Scales the number of emitted particles. You can enter a value between 0 and 1 to scale the emission rate between 0 and 100%. Scaling down the emission rate speeds scene play.
Inherit Opacity: Gives the particles the texture’s transparency using the alpha information—Alpha Gain, Alpha Offset, and Contrast (if present). If you turn on Inherit Opacity, you can use the following attributes:
Use Luminance: Uses the texture’s luminance rather than alpha information as the source of transparency.
Invert Opacity: Gives the particles a transparency opposite the texture’s transparency, whether from alpha or luminance.