| Attribute long name (and short name) | Description | Data Type | 
                  
                     | acceleration (acc) | Sets the rate of change of velocity on a per
                           particle basis.
                         | vector array | 
                  
                     | age (ag) | Contains the number of seconds each particle
                           in the object has existed since the first frame. This is a read-only attribute.
                         | float array | 
                  
                     | attributeName* | Specifies the name of the attribute whose values
                           are to be displayed at particle positions. By default, particle
                           id numbers are displayed. Valid for Numeric render
                           type.
                         | string | 
                  
                     | betterIllumination* | Provides smoother lighting and shadowing at
                           the expense of increased processing time. Valid for Cloud render type.
                         | boolean | 
                  
                     | birthPosition | Stores the position at which each particle was
                           born in the particle’s local space. 
                         | vector array | 
                  
                     | birthTime
                           (bt)
                         | Contains the Current Time value
                           at which each particle in the object was created. This is a read-only
                           attribute.
                         | float array | 
                  
                     | cacheData (chd) | Turns on or off dynamic state caching for the
                           object.
                         | boolean | 
                  
                     | castsShadows (rsh) | Turns on or off the object’s ability to cast
                           shadows in software rendered images. Valid for Cloud, Blobby Surface,
                           and Tube render types.
                         | boolean | 
                  
                     | centroidX, centroidY, centroidZ (ctdx, ctdy, ctdz) | Contains the X, Y, and Z elements of the average
                           position of its particles. These are read-only attributes.
                         | float | 
                  
                     | collisionFriction
                           (cfr)
                         | Sets how much the colliding particle’s velocity
                           parallel to the surface decreases or increases as it bounces off the
                           collision surface. This attribute is displayed as Friction in
                           the user interface. It works on a per geometry basis.
                         | float (multi) | 
                  
                     | collisionResilience (crs) | Sets how much rebound occurs when particles
                           collide with a surface. This attribute is listed as Resilience in
                           the user interface. It works on a per geometry basis. 
                         | float (multi) | 
                  
                     | collisionU, collisionV* | U and V positions of the NURBS surface where
                           a particle collided in the current frame. For polygonal surfaces, the
                           values are always 0. The values are reset to -1 at the start of
                           each frame. Values change only in frames where collision occurs.
                           These are read-only attributes. 
                         | float  | 
                  
                     | colorAccum* | Adds the RGB components of overlapping particles.
                           Also adds opacity values of overlapping particles. Generally, colors
                           become brighter and more opaque as they overlap. To see the effect
                           of Color Accum, you must add an
                           opacity attribute to particles displayed as Points.
                           Valid for MultiPoint, MultiStreak, Points,
                           and Streak render types.
                         | boolean | 
                  
                     | colorBlue* | Sets blue component of RGB color. Valid for
                           all render types except Numeric and Tube.
                         | float | 
                  
                     | colorGreen* | Sets green component of RGB color. Valid for
                           all render types except Numeric and Tube.
                         | float | 
                  
                     | colorRed* | Sets red component of RGB color. Valid for all
                           render types except Numeric and Tube.
                         | float | 
                  
                     | conserve
                           (con)
                         | Sets how much of a particle object’s velocity
                           attribute value is retained from frame to frame. 
                         | float | 
                  
                     | count
                           (cnt)
                         | Contains the total number of particles in the
                           object. This is a read-only attribute.
                         | integer | 
                  
                     | currentTime (cti) | Sets the time value for the particle object’s
                           independent clock.
                         | time | 
                  
                     | depthSort (ds) | Turns on or off depth sorting of particles for
                           rendering. This prevents unexpected colors when you hardware render
                           overlapping colored, transparent particles. Valid for MultiPoint, MultiStreak, Points, Streak,
                           and Sprites render types.
                         | boolean | 
                  
                     | dynamicsWeight (dw) | Scales the effect of fields, collisions, springs,
                           goals, and emission on particles.
                         | float | 
                  
                     | emissionInWorld (eiw) | When
                           on, emission occurs in the world coordinate system. This is the
                           default setting. When off, emission occurs in the emitted particle
                           object’s local space. 
                         | boolean | 
                  
                     | emitterRatePP* | Sets the per particle emission rate. | float array | 
                  
                     | enforceCountFromHistory
                           (ecfh)
                         | In a soft body, if you change the original geometry’s
                           construction history in a way that alters the number of CVs, vertices,
                           or lattice points, Maya updates the number of particles of the soft
                           body correspondingly.
                         | boolean | 
                  
                     | event* | Contains the number of times each particle in
                           the object has hit something. This is a read-only attribute.
                         | float array | 
                  
                     | expressionsAfterDynamics
                           (ead)
                         | Sets whether expressions are evaluated before
                           or after other dynamics.
                         | boolean | 
                  
                     | force (frc) | Contains
                           the accumulation of all forces acting on the particle object. This
                           is a read-only attribute. If you use this attribute in an expression,
                           first turn on expressionsAfterDynamics.
                         | vector array | 
                  
                     | forcesInWorld (fiw) | Sets whether forces are applied to the object
                           in world space or in its local space.
                         | boolean | 
                  
                     | goalActive (ga) | For a goal object, turns each goal on or off.
                           It has the same effect as setting the corresponding goalWeight to
                           0, except the animation processing is more efficient. This attribute
                           works on a per object basis.
                         | boolean (multi) | 
                  
                     | goalOffset* | Sets an offset to the world space position of
                           the goal object.
                         | vector array | 
                  
                     | goalPP* | Sets how much the particles try to follow the
                           goal on a per particle basis.
                         | float array | 
                  
                     | goalSmoothness (gsm) | Sets how smoothly goal forces change as the
                           goal weight changes from 0 to 1. The higher the number, the smoother the
                           change.
                         | float | 
                  
                     | goalU,
                           goalV*
                         | Set the exact locations on a NURBS surface where
                           the particles are attracted.
                         | float array | 
                  
                     | goalWeight (gw) | Sets how much all particles of the object are
                           attracted to the goal.
                         | float (multi) | 
                  
                     | incandescencePP* | Sets glow color in conjunction with a software
                           rendering Particle Incand Mapper Node (see
                           Rendering.) Valid for Cloud and Tube render types.
                         | vector array | 
                  
                     | inheritFactor (inh) | Sets the (decimal) fraction of velocity an emitted
                           particle object inherits from an emitter. 
                         | float | 
                  
                     | inputGeometrySpace (igs) | For a soft body, this sets the coordinate space
                           Maya uses to position point data provided by the input geometry
                           to the particle shape.
                         | integer | 
                  
                     | isDynamic (isd) | Turns on or off dynamic animation of the object.  | boolean | 
                  
                     | isFull
                           (ifl)
                         | Contains 1 if an emitted particle shape is full,
                           or 0 if not full. An emitted particle shape is full when the number of
                           emitted particles equals the maxCount. This is a read-only attribute.
                         | boolean | 
                  
                     | lifespan* | Sets when all particles in the object die. | float | 
                  
                     | lifespanPP* | Sets when particles die on a per particle basis. | float array | 
                  
                     | levelOfDetail (lod) | Scales the number of particles that can be emitted
                           into the emitted particle object. 
                         | float | 
                  
                     | lineWidth * | Sets the width of streaking particles. Valid
                           for MultiStreak and Streak render
                           types.
                         | float | 
                  
                     | mass
                           (mas)
                         | Specifies the physical mass of particles. Mass
                           values affect the results of dynamic calculations. By default, each particle
                           of a particle object has a mass of 1.
                         | float array | 
                  
                     | mass0
                           (mas0)
                         | Initial state counterpart to mass. | float array | 
                  
                     | maxCount (mxc) | Sets a limit on the number of particles the
                           emitted particle shape accepts from an emitter.
                         | int | 
                  
                     | multiCount* | Sets number of points you want displayed for
                           each particle in the object. Valid for MultiPoint and Points render
                           types.
                         | float | 
                  
                     | multiRadius* | Sets radius of spherical region in which particles
                           are randomly distributed. Valid for MultiPoint and MultiStreak render types.
                         | float | 
                  
                     | needParentUV* | Turns
                           on or off the ability to read the parentU and parentV attributes.
                           If you add a surface emitter to a NURBS or polygonal
                              surface, parentU and parentV contain the UV coordinates where
                           each particle was emitted. You can use these attributes in expressions and
                           MEL scripts.
                         | boolean | 
                  
                     | normalDir* | Sets direction of normal for particles. Use
                           with useLighting. Valid for MultiPoint, MultiStreak, Points,
                           and Streak render types.
                         | integer (1-3) | 
                  
                     | opacity* | Sets amount of transparency for all particles
                           in the object. Valid for all render types except Numeric and Tube.
                         | float | 
                  
                     | opacityPP* | Sets amount of transparency on a per particle
                           basis. Valid for all render types except Numeric, Tube,
                           and Blobby Surface.
                         | float array | 
                  
                     | particleId
                           (id)
                         | Contains the id number of each particle. Valid
                           for Numeric render type. This is
                           a read-only attribute.
                         | float array | 
                  
                     | parentId* | If you emit from a particle object, this contains
                           the id of all particles that emit the particles. You can use the
                           id to query the emitting object’s attribute values, for example,
                           acceleration, velocity, and lifespanPP. This is a read-only attribute. 
                         Note that if you use the MEL emit command to
                           create the particles that emit, the parentId attribute of those emitted
                           particles is always 0.
                         | float array | 
                  
                     | parentU, parentV* | If
                           you add a surface emitter to a NURBS or polygonal
                              surface, these attributes contain the UV coordinates
                           where each particle was emitted. To use these read-only attributes,
                           you must turn on Need Parent UV in the emitter.
                           You can use these attributes in expressions and MEL scripts.
                         | float array | 
                  
                     | particleRenderType* | Sets render display type of particles, for example, Streak. 
                         | integer | 
                  
                     | pointSize* | Sets how large particles are displayed. Valid
                           for MultiPoint, Numeric,
                           and Points render types.
                         | float | 
                  
                     | position (pos) | Sets the object position in local space coordinates
                           on a per particle basis.
                         | vector array | 
                  
                     | position0
                           (pos0)
                         | Initial state counterpart to position. | vector array | 
                  
                     | radius* | Sets radius size of all particles. Valid for Blobby
                              Surface, Cloud, and Sphere render
                           types.
                         | float | 
                  
                     | radius0* | Sets starting point radius for Tube render
                           type. 
                         | float | 
                  
                     | radius1* | Sets ending point radius for Tube render
                           type. 
                         | float | 
                  
                     | radiusPP* | Sets radius size on a per particle basis. Valid
                           for Blobby Surface, Cloud,
                           and Sphere, render types.
                         | float array | 
                  
                     | rampAcceleration (rac) | Controls acceleration with a ramp. Any other
                           animation of acceleration is added to the ramp-controlled acceleration.
                         | vector array | 
                  
                     | rampPosition
                           (rps)
                         | Controls position with a ramp. Any other animation
                           of position is added to the ramp-controlled position.
                         | vector array | 
                  
                     | rampVelocity
                           (rvl)
                         | Controls velocity with a ramp. Any other animation
                           of velocity is added to the ramp-controlled velocity.
                         | vector array | 
                  
                     | rgbPP* | Sets color on a per particle basis. Valid for MultiPoint, MultiStreak, Points, Spheres, Sprites,
                           and Streak render types.
                         | vector array | 
                  
                     | seed
                           (sd)
                         | Sets the id of the random number generator of
                           the associated emitter. This attribute works on a per object basis.
                         | float (multi) | 
                  
                     | sceneTimeStepSize (sts) | Contains the value of the time difference between
                           the last displayed frame and current frame. This contains 1 if you’re
                           simply playing the animation or clicking the frame forward or backward
                           button. If you click widely separated frames in the Time Slider,
                           the attribute contains the difference in time between the two frames.
                           This is a read-only attribute.
                         | time (in current units) | 
                  
                     | selectedOnly* | Turns on or off display of id numbers only for
                           selected particles. Valid for Numeric render
                           type. 
                         | boolean | 
                  
                     | spriteNum* | Sets the image number index for a Sprite image
                           sequence. 
                         | integer | 
                  
                     | spriteNumPP* | Sets the image number index for a Sprite image
                           sequence on a per particle basis. 
                         | integer array | 
                  
                     | spriteScaleX, spriteScaleY* | Sets the Sprite X-
                           and Y-axis image scale. 
                         | float | 
                  
                     | spriteScaleXPP, spriteScaleYPP* | Sets the Sprite X-
                           and Y-axis image scale on a per particle basis. 
                         | float array | 
                  
                     | spriteTwist* | Sets the Sprite image’s
                           rotation angle. 
                         | float | 
                  
                     | spriteTwistPP* | Sets the Sprite image’s
                           rotation angle on a per particle basis. 
                         | float array | 
                  
                     | startFrame (stf) | Sets the animation frame after which dynamics
                           (including emission) are computed for the object.
                         | float | 
                  
                     | surfaceShading* | Sets how sharply the spheres of Cloud render
                           type are displayed. Use a value between 0 and 1. A value of 1 displays spheres
                           more distinctly; a value of 0 creates a cloudier effect.
                         | float | 
                  
                     | tailFade* | Sets the opacity of tail fade. Valid for MultiStreak and Streak render
                           types.
                         | float | 
                  
                     | tailSize* | Sets the length of the tails for MultiStreak, Streak,
                           and Tube render types.
                         | float | 
                  
                     | targetGeometrySpace (tgs)  | For a soft body, sets the coordinate space Maya
                           uses to position point data provided by the particle shape to the target
                           geometry. 
                         | integer | 
                  
                     | threshold* | Controls surface blending between Cloud or Blobby surface
                           spheres. This is a read-only attribute.
                         | float | 
                  
                     | timeStepSize
                           (tss)
                         | Contains the animation frame increment in current
                           units. For example, if your animation is set to Film
                              (24 fps), timeStepSize has a value of
                           1 (frame). 
                         Keying or otherwise setting the Current
                              Time value alters the timeStepSize. For instance, with
                           a frame rate of 24 frames per second, suppose you set the Current
                              Time to 0 at frame 0, and to 100 at frame 50. Because
                           you’re compressing twice as much time between frames 0 and 50, the timeStepSize is
                           twice as large, in other words, 2. This is a read-only attribute.
                         | time | 
                  
                     | totalEventCount (evc) | Contains total events that have occurred for
                           all particles of the object. This is a read-only attribute.
                         | integer | 
                  
                     | traceDepth (trd) | Sets the maximum number of collisions Maya can
                           detect for the object in each animation time step.
                         | integer | 
                  
                     | traceDepthPP* | Sets the trace depth on a per particle basis. | float array | 
                  
                     | UseCurrentUVSet | Selects the UV set on the poly emitter that
                           is used for textured emission effects. The same UV set is used for
                           all textures attached to all textured emission effects (color/opacity
                           and emission rate). If the UseCurrentUVSet option
                           is selected, then the active UV set on the surface emitter is used.
                         | boolean | 
                  
                     | useLighting* | Turns on or off whether scene lighting lights
                           up particles. Valid for MultiPoint, MultiStreak, Points, Sprites,
                           and Streak render types.
                         | boolean | 
                  
                     | userScalar1PP userScalar2PP userScalar3PP userScalar4PP userScalar5PP | Predefined outputs for user-defined attributes
                           used in Particle Sampler Info node.
                         | float array | 
                  
                     | userVector1PP userVector2PP userVector3PP userVector4PP userVector5PP | Predefined outputs for user-defined attributes
                           used in Particle Sampler Info node.
                         | vector array | 
                  
                     | velocity
                           (vel)
                         | Sets speed and direction on a per particle basis. | vector array | 
                  
                     | velocity0
                           (vel0)
                         | Initial state counterpart to velocity | vector array | 
                  
                     | visibleInReflections (rrl) | Turns on or off whether the object is visible
                           in reflections when software rendered. Valid for Cloud, Blobby Surface,
                           and Tube render types.
                         | boolean | 
                  
                     | visibleInRefractions (rrr) | Turns on or off whether the object is visible
                           in refractions when software rendered. Valid for Cloud, Blobby Surface,
                           and Tube render types
                         | boolean | 
                  
                     |  worldBirthPosition | Stores the position at which each particle was
                           born in world space.
                         | vector array | 
                  
                     | worldCentroidX, worldCentroidY, worldCentroidZ (wctx,
                           wcty, wctz)
                         | Contains the world space X, Y, and Z elements
                           of the average position of its particles. These attributes are a
                           read-only attributes.
                         | float | 
                  
                     | worldPosition (wps) | Contains the world space counterpart to position.
                           This is a read-only attribute.
                         | vector array | 
                  
                     | worldVelocity (wvl) | Contains the world space counterpart to velocity.
                           This is a read-only attribute.
                         | vector array | 
                  
                     | worldVelocityInObjectSpace
                           (wvo)
                         | Contains the local space equivalent to the object’s
                           world space velocity. This is a read-only attribute.
                         | vector array |