Attribute

Description

Data Type

Belongs to

Geometry Types

Attribute Type

R/W or RO

Age

Time in seconds since a particle was emitted.

The Emitter compounds typically set this attribute to a fraction of a frame to simulate a continuous emission.

scalar

points

point cloud

predefined

read/write

AgeLimit

The maximum age of a particle in seconds.

This attribute is automatically set by some of the Emitter compounds.

This attribute must be set to use compounds that set values based on age percentage, such as Modulate value by Age Percentage.

Particles are not deleted automatically when they reach AgeLimit. There must be nodes in a tree to specifically delete the particles, such as Delete Particle at Age Limit.

scalar

points

point cloud

custom

read/write

AngularVelocity

The angular velocity of a point.

The Simulate Rigid Bodies node uses this attribute to update Orientation, and sets it based on collisions.

rotation

points

point cloud

polygon mesh

NURBS surface

NURBS curve

lattice

predefined

read/write

Area

Area of a polygon mesh object in Softimage units squared.

scalar

objects

polygon mesh

inherent

read-only

BlobBlend

Determines the amount of blending between particles. A high value creates more blending between the particles, but takes longer to render because more surface area is drawn. To see particles displayed as blobs, you must draw a render region.

scalar

points

point cloud

predefined

read/write

CollisionLocation

Available to store the location of a collision.

This attribute is used by some of the factory compounds.

location

points

point cloud

polygon mesh

NURBS surface

NURBS curve

lattice

predefined

read/write

CollisionScale

The scaling of a point's size in the XYZ axes used by the Simulate Rigid Bodies node for determining collisions.

The final size of a particle for collisions is the product of CollisionSize and CollisionScale. If CollisionSize is not defined, then Size is used, and if neither CollisionSize nor Size is defined then 0.001 is used. If CollisionScale is not defined, then Scale is used, and if neither is defined then (1, 1, 1) is used.

For example, setting this value allows you to use a slightly larger size for collisions than for rendering and display, reducing interpenetration. You can also scale by different values in different axes for oblong collision shapes that cannot be defined by Size or CollisionSize alone.

3D vector

points

point cloud

polygon mesh

NURBS surface

NURBS curve

lattice

predefined

read/write

CollisionShape

The shape used by the Simulate Rigid Bodies node for determining collisions.

If this attribute is not defined, Shape is used instead. Setting this value allows you to use a simpler shape for collisions than for rendering and display, reducing the amount of computation required.

Only Box and Sphere are valid values:

• Disc and Rectangle are approximated by Box.

• Cone, Cylinder, Segment, Capsule, and Blob are approximated by Sphere.

• Point is approximated by a very small Sphere.

• Instances are approximated by their bounding box.

shape

points

point cloud

polygon mesh

NURBS surface

NURBS curve

lattice

predefined

read/write

CollisionSize

The base radius of a shape used by the Simulate Rigid Bodies node for determining collisions. You can further modify the size used for collisions using CollisionScale, which allows you to scale by different values in each of the three axes.

The final size of a particle for collisions is the product of CollisionSize and CollisionScale. If CollisionSize is not defined, then Size is used, and if neither CollisionSize nor Size is defined then 0.001 is used. If CollisionScale is not defined, then Scale is used, and if neither is defined then (1, 1, 1) is used.

Setting CollisionSize allows you to use a slightly larger size for collisions than for rendering and display, reducing interpenetration.

scalar

points

point cloud

polygon mesh

NURBS surface

NURBS curve

lattice

predefined

read/write

Color

The color of particles in the viewport.

By default, the color is not used for rendering unless you are using a shader that is especially written to use this attribute. Otherwise, you can get the Color attribute in a render tree using a Color Attribute shader.

This attribute is available to be defined on points of objects other than point clouds, but it isn't used in those cases.

color

points

point cloud

predefined

read/write

Colors

The color value of a vertex color property.

color

samples

vertex colors

inherent

read/write

CurveLength

The length of a curve in Softimage units.

scalar

objects

NURBS curve

inherent

read-only

DragCoefficient

The factor by which points are affected by drag.

This value is used by the Wind, Fan, and Eddy force objects in conjunction with the Size to determine the drag force.

scalar

points

point cloud

polygon mesh

NURBS surface

NURBS curve

lattice

predefined

read/write

DynamicFriction

The coefficient of dynamic friction. This attribute is used by the Simulate Rigid Bodies node to calculate particle motion.

When two bodies collide or slide against each other, dynamic friction creates a decelerating force. The force is in the opposite direction to motion along the plane of contact. It is proportional to the product of the coefficient and the component of force that is pushing the bodies together (e.g., the weight of an object on a sloping surface).

When two bodies interact, the coefficient of dynamic friction for their interaction is the product of their respective DynamicFriction values.

If this attribute is not defined, the default value used by the Simulate Rigid Bodies node is 0.5.

scalar

points

point cloud

polygon mesh

NURBS surface

NURBS curve

lattice

predefined

read/write

EdgeCrease

The edge crease value for subdivision surfaces. Edges marked as hard have an edge crease value of 10.

scalar

edges

polygon mesh

inherent

read/write

EdgeIsHard

Whether an edge has been marked as hard.

Boolean

edges

polygon mesh

inherent

read/write

EdgeLength

The length of an edge in Softimage units.

If you get this value at a surface location, the value is interpolated from the nearby edges and so doesn't necessarily correspond to the actual length of any edge on the object.

scalar

edges

polygon mesh

inherent

read-only

EdgeNormal

The surface normal at the midpoints of edges.

3D vector

edges

polygon mesh

inherent

read-only

EdgePosition

The positions of the edge midpoints.

3D vector

edges

polygon mesh

inherent

read-only

EdgeReferenceFrame

A 3x3 matrix representing the orientation of an edge. The rows of the matrix represent the XYZ axes. These are equivalent to the axes displayed on manipulators when you transform a component in Local mode.

You could use this, for example, if you wanted to place particles at specific offsets from a polygon mesh's edges.

3x3 matrix

edges

polygon mesh

inherent

read-only

Elasticity

Controls the ratio of velocities after a collision (coefficient of restitution). This attribute is used by the Simulate Rigid Bodies node to calculate particle motion.

When two bodies collide, the elasticity of the interaction is the product of the elasticities of the two bodies.

In a head-on collision at a value of 1.0, the velocities stay the same as before the collision but with opposite directions. At a value of 0.0, colliding particles stick to each other and share the same velocity after the collision. Values above 1 mean that that particles increase their energy each time they collide.

If this attribute is undefined, the default value used by the Simulate Rigid Bodies node is 0.5.

Note that energy and momentum cannot be transferred to an obstacle object; they can only be transferred between two colliding particles.

scalar

points

point cloud

polygon mesh

NURBS surface

NURBS curve

lattice

predefined

read/write

EmitLocation

The location on a surface at which a particle was emitted.

When emitting from a volume, the location is an offset from the object center and is not affected by deformation.

This attribute has no meaning when emitting from nulls or explicitly defined numeric positions such as (1.0, 2.0, 3.0).

location

points

point cloud

predefined

read/write

EmitPosition

The position at which a particle was originally emitted.

This attribute is set automatically by the Emitter compounds. Unlike EmitLocation, it does not move with an animated or deformed geometry.

3D vector

points

point cloud

custom

read/write

Force

The force applied to a point. This value, together with the point's mass, is used by the Simulate Particles and Simulate Rigid Bodies nodes to calculate the acceleration and update the velocity.

Note that this attribute is set to 0.0 at the end of every frame.

3D vector

points

point cloud

polygon mesh

NURBS surface

NURBS curve

lattice

predefined

read/write

GoalLocation

Available to store a location on a surface towards which you want a point to move.

This attribute is used by some of the factory compounds.

This attribute is not considered by the Simulate Particles node. There must be other nodes in a graph to set the Force or PointVelocity to get a point moving toward its goal.

location

points

point cloud

polygon mesh

NURBS surface

NURBS curve

lattice

predefined

read/write

GoalPosition

A position towards which you want a point to move.

This attribute is used by some of the Goal compound as an alternative to GoalLocation. Unlike GoalLocation, , it does not move with an animated or deformed geometry (although it might appear that way if it gets reset every frame).

3D vector

points

point cloud

polygon mesh

NURBS surface

NURBS curve

lattice

custom

read/write

ID

A unique identifier for each point in a point cloud. If you delete and add points in a cloud, indices may get re-used but the IDs will not.

The ID is automatically set by the Add Point and Clone Point nodes, as well as by compounds that contain them. You cannot set this attribute manually.

Even though it appears as though this attribute is available for points on objects other than point clouds, it doesn't exist and cannot be set or initialized in those cases.

integer

points

point cloud

predefined

read-only

Init

False if a point was created on the current frame, true otherwise. This attribute is automatically set by the Add Point and Clone Point nodes, as well as by compounds that contain them.

You can use this attribute to distinguish between new and old particles. For example, you can set data only on new particles even in compounds that don't have access to the On Execute ports of Add Point and Clone Point.

Boolean

points

point cloud

predefined

read/write

Init_Color

A particle's original Color value when it was emitted.

This attribute is set by the Emitter compounds, and can be used by Modify Particle Color or your own compounds.

color

points

point cloud

custom

read/write

Init_Force

A particle's original Force value when it was emitted.

This attribute is set by the Emitter compounds, and can be used by your own compounds.

3D vector

points

point cloud

custom

read/write

Init_Mass

A particle's original Mass value when it was emitted.

This attribute is set by the Emitter compounds, and can be used by your own compounds.

scalar

points

point cloud

custom

read/write

Init_Orientation

A particle's original Orientation value when it was emitted.

This attribute is set by the Emitter compounds, and can be used by your own compounds.

rotation

points

point cloud

custom

read/write

Init_PointVelocity

A particle's original PointVelocity value when it was emitted.

This attribute is set by the Emitter compounds, and can be used by Move Toward Goal, Modulate Velocity Over Time, or your own compounds.

3D vector

points

point cloud

custom

read/write

Init_Scale

A particle's original Scale value when it was emitted.

This attribute is set by the Emitter compounds, and can be used by your own compounds.

3D vector

points

point cloud

custom

read/write

Init_Size

A particle's original Size value when it was emitted.

This attribute is set by the Emitter compounds, and can be used by Modulate Particle Size or your own compounds.

scalar

points

point cloud

custom

read/write

IntersectionLocation

Used internally by certain compounds.

location

points

point cloud

custom

read/write

IntersectionVelocity

Used internally by certain compounds.

location

points

point cloud

custom

read/write

IsElem

True if a component is a member of the corresponding cluster, and false otherwise.

Boolean

components

cluster

predefined

read-only

IsHomogeneous

Indicates whether a texture projection uses homogeneous coordinates (true) or not. Softimage automatically uses homogeneous coordinates for camera projections and stores the distance to the camera (q) in the W coordinate.

Boolean

objects

texture UV coordinates

inherent

read-only

IsSpatial

Indicates whether a texture projection is spatial (true) or not. In spatial coordinates, W stores the third axis, rather than the distance from the camera as in homogeneous coordinates.

Boolean

objects

texture UV coordinates

inherent

read-only

isStuck

Whether a particle is stuck (true) or not.

This attribute is used by the Stick to Location, Stick to Surface, and Unstick from Surface compounds. You can also get this attribute and use it to do other things with stuck and unstuck particles.

Boolean

points

point cloud

custom

read/write

LocalTime

The time that has passed since the start of the simulation. Objects in different environments can have different LocalTime values.

scalar

objects

any object with a Simulation region in the construction stack

inherent

read-only

Mass

The mass of a point. Used by the Simulate Particles and Simulate Rigid Bodies nodes as well as several compounds to calculate the effect of forces.

If Mass is not defined, the Simulate Particles node uses a default of 1.0, so that forces have a one-to-one effect on velocity.

The Simulate Rigid Bodies node uses a default of 0.1 if Mass is undefined.

If Mass is defined but equal to 0.0, forces have no effect using either of the Simulation nodes.

scalar

points

point cloud

polygon mesh

NURBS surface

NURBS curve

lattice

predefined

read/write

MaxWeight

The maximum weight of a weight map.

scalar

objects

weight map

inherent

read/write

MinWeight

The minimum weight of a weight map.

scalar

objects

weight map

inherent

read/write

NbEdges

The total number of edges in a polygon mesh.

integer

objects

polygon mesh

inherent

read-only

NbElem

The total number of members in a cluster.

integer

objects

cluster

inherent

read-only

NbPoints

The total number of points on a geometric object.

integer

objects

point cloud

polygon mesh

NURBS surface

NURBS curve

lattice

inherent

read-only

NbPolygonNodes

The total number of polygon nodes (texture samples) on a polygon mesh. There is one polygon node for every corner of a polygon. Each vertex has as many polygon nodes as there are adjacent polygons.

integer

objects

polygon mesh

inherent

read-only

NbPolygons

The total number of polygons in a polygon mesh object.

integer

objects

polygon mesh

inherent

read-only

NbSamplePoints

The total number of texture sample points on a NURBS surface or curve.

integer

objects

NURBS surface

NURBS curve

inherent

read-only

NbSubCurves

The total number of subcurves in a curve object.

integer

objects

NURBS curve

inherent

read-only

NbSubSurfaces

The total number of subsurfaces in an assembled NURBS surface mesh.

integer

objects

NURBS surface

inherent

read-only

NodeLocation

The locations of polygon nodes (also called polynodes or texture sample points) on a polygon mesh. This is useful for getting values of vertex color properties (CAVs).

location

samples

polygon mesh

inherent

read-only

NodeNormal

The normals at the polygon nodes (texture samples). These are the normals used for shading, and are the same as the normals that are displayed in a geometry view when you choose Normals from the Show menu (eye icon).

If you display NodeNormal in the 3D views, they may not appear to update properly when you modify the automatic discontinuity settings (in the Geometry Approximation property editor) unless you are in a shaded mode. You may also need to force an update to the ICE tree, for example, by disconnecting and then reconnecting relevant nodes.

3D vector

samples

polygon mesh

inherent

read-only

NodePosition

The position of polygon nodes (texture samples).

3D vector

samples

polygon mesh

inherent

read-only

Normals

The normals stored in a user normal property.

3D vector

samples

user normal property

inherent

read/write

Orientation

Used to align particle shapes and sprites.

This attribute is updated automatically by the Simulate Rigid Bodies node based on AngularVelocity and the effect of collisions.

Normally, the reference frame for the orientation is the point cloud's local space.

With strands, Orientation is used to align the base particle and StrandOrientation is used to align the shapes at the StrandPosition values. If StrandDeform is true, the reference frame for both Orientation and StrandOrientation is established by using the strand's tangent as the Y axis. PointUpVector and StrandUpVector define the X axis. If the up-vector attributes are not defined, the up-vector is calculated from the camera, which will make the deformations rotate if the camera moves.

rotation

points

point cloud

predefined

read/write

PointBinormal

The binormals at locations along curve.

These values are calculated directly from the NURBS equations instead of being interpolated from surrounding points.

If you get this attribute by an explicit string reference, for example Get Data ("curve.PointBinormal"), the context is per point and the values represent the values of the NURBS hull (control polyline) at the control points (CVs) rather than values on the curve itself.

3D vector

points

NURBS curve

inherent

read-only

PointCrease

The crease value at vertices on a polygon mesh.

scalar

points

polygon mesh

inherent

read/write

PointLocation

The location of vertices on a polygon mesh.

This is useful for getting values of weight maps.

location

points

polygon mesh

predefined

read-only

PointNeighbors

An array containing the locations of the vertices that are connected to a vertex by edges.

If you get this attribute at a surface location, it returns the neighbors of the vertex closest to the location.

array of locations

points

polygon mesh

inherent

read-only

PointNormal

The smoothed normal at locations on a geometry.

If you get this attribute at locations on a NURBS surface or curve, the values are calculated directly from the NURBS equations instead of being interpolated from surrounding points.

If you get this attribute on a NURBS surface or curve by an explicit string reference, for example Get Data ("curve.PointNormal"), the context is per point and the values represent the values of the NURBS hull (control polyline) at the control points (CVs) rather than values on the curve or surface itself.

3D vector

points

polygon mesh

NURBS surface

NURBS curve

inherent

read-only

PointPosition

The position of points. To deform a geometric object, you must set this attribute.

This attribute is updated automatically by the Simulate Particles and Simulate Rigid Bodies nodes based on PointVelocity.

You can also get this attribute at an arbitrary surface location to return the position of that location, even if it does not correspond to an actual geometric point.

3D vector

points

point cloud

polygon mesh

NURBS surface

NURBS curve

lattice

inherent

read/write

PointReferenceFrame

A 3x3 matrix representing the orientation of a point. The rows of the matrix represent the XYZ axes. These are equivalent to the axes displayed on manipulators when you transform a component in Local mode.

You could use this, for example, if you wanted to place particles at specific offsets from a polygon mesh's points.

3x3 matrix

points

polygon mesh

NURBS surface

NURBS curve

inherent

read-only

PointTangent

Tangent at locations along a curve.

If you get this attribute by an explicit string reference, for example Get Data ("curve.PointTangent"), the context is per point and the values represent the values of the NURBS hull (control polyline) at the control points (CVs) rather than values on the curve itself.

3D vector

points

NURBS curve

inherent

read-only

PointU

The NURBS U parameter value along a curve.

If you get this attribute by an explicit string reference, for example Get Data ("curve.PointU"), the context is per point and the values represent the values of the NURBS hull (control polyline) at the control points (CVs) rather than values on the curve itself.

scalar

points

NURBS curve

inherent

read-only

PointUpVector

Used to establish a reference frame for Orientation on the base particle when using strands and StrandDeform is true.

The strand tangent defines the Y axis and this attribute represents the X axis.

If this attribute is not defined, the up-vector is calculated from the camera view, which will make the deformations rotate if the camera moves.

3D vector

points

point cloud

predefined

read/write

PointUV

The NURBS UV parameter values on a surface.

If you get this attribute by an explicit string reference, for example Get Data ("surface.PointUV"), the context is per point and the values represent the values of the NURBS hull at the control points (CVs) rather than values on the surface itself.

2D vector

points

NURBS surface

inherent

read-only

PointVelocity

The velocity of points.

This attribute is automatically updated by the Simulate Particles and Simulate Rigid Bodies nodes based on Force and Mass.

3D vector

points

point cloud

polygon mesh

NURBS surface

NURBS curve

lattice

predefined

read/write

PolygonArea

The area of a polygon in Softimage units squared.

scalar

polygons

polygon mesh

inherent

read-only

PolygonNormal

The normal of a polygon. This is the same normal that is displayed when you activate Polygon Normals in a 3D view's Show menu (eye icon).

3D vector

polygons

polygon mesh

inherent

read-only

PolygonPosition

The position of the midpoint of a polygon.

3D vector

polygons

polygon mesh

inherent

read-only

PolygonRefFrame

A 3x3 matrix representing the orientation of a polygon. The rows of the matrix represent the XYZ axes. These are equivalent to the axes displayed on manipulators when you transform a component in Local mode.

You could use this, for example, if you wanted to place particles at specific offsets from a polygon mesh's polygon.

3x3 matrix

polygons

polygon mesh

inherent

read-only

positions

The position of points in a shape key. The meaning of the data depends on the shape reference mode. To determine the reference mode, get the shape key's Cluster Key Reference Mode (KeyType).

• If the shape key is in Object reference mode (KeyType = 2), values are offsets from the undeformed point positions in the object's local coordinates.

• If the shape key is in Local reference mode (KeyType = 1), values are offsets from the undeformed point positions, but are expressed relative to each point's own referential (PointReferenceFrame).

• If the shape key is in Absolute reference mode (KeyType = 0), values are point positions (not offsets) in the object's local coordinates.

3D vector

points

shape key

inherent

read/write

Scale

A scaling factor applied to particles' size. This lets you scale by different values in different axes to create oblong shapes.

This attribute is used for display and rendering, as well as by the Simulate Rigid Bodies node for determining collisions if CollisionScale is undefined.

If neither this attribute nor CollisionScale is defined, the default value used by the Simulate Rigid Bodies node is (1, 1, 1).

3D vector

points

point cloud

predefined

read/write

Shape

The shape of particles.

This attribute is used for rendering and display.

It is also used by the Simulate Rigid Bodies node for determining collisions.

shape

points

point cloud

predefined

read/write

ShapeInstanceTime

The "local" time of particle instances, in seconds. This is used to control shape animation and sprite sequences on individual instances.

If this attribute is defined, then the instances are implemented through assemblies when rendering with mental ray. There is a limitation in that these don't get called when generating lightmaps.

scalar

points

point cloud

predefined

read/write

SimulatedFrameFraction

The fraction of a frame that has already been simulated for a point.

This value is used by the Simulate Particles node. It will simulate particles only for the remainder of the frame. When done, the Simulate Particles node sets this value to 1.0 to avoid having the particle simulated again by another Simulate Particles node later in the same tree or another tree.

The Emitter compounds automatically set SimulatedFrameFraction to (1 – Age/SimulationStep) so that on its first frame of existence, a particle moves only for a distance proportional to its age. As a result, it appears as if particles have been emitted continuously throughout the frame instead of all at once.

You can modify and set this attribute, for example, if you want to change states after a mid-frame event such as a collision or randomized timer, and then continue simulating in the second state for the rest of the frame. This helps to avoid issues with stratification and discretization that might occur if particles changed state all at the same time within a frame. Use values between 0.0 and 1.0 only.

scalar

points

point cloud

polygon mesh

NURBS surface

NURBS curve

lattice

predefined

read/write

Size

The radius of particle shapes.

This is used for display and rendering, as well as by the Simulate Rigid Bodies node for determining collisions if CollisionSize is undefined.

If both this attribute and CollisionSize are undefined, the default value used by the Simulate Rigid Bodies node is 0.001.

scalar

points

point cloud

predefined

read/write

SlideLocation

Used internally by certain compounds.

location

points

point cloud

custom

read/write

Spawned

Whether a particle has been spawned (true) or not.

This attribute is set and used by the Spawning compounds to prevent spawned particles from spawning themselves. You can also use the Test Is Spawned Particle compound to use this attribute to do other things with spawned or unspawned particles.

Boolean

points

point cloud

custom

read/write

SplashCollisionForce

Used internally by certain compounds.

3D vector

points

point cloud

custom

read/write

SplashIntersection

Used internally by certain compounds.

location

points

point cloud

custom

read/write

SpriteAngle

Not used.

scalar

points

point cloud

predefined

read/write

State_ID

The current state of a particle.

This attribute is set and used by the State compounds. You can get and set this attribute manually, but it's probably easier and less error-prone to use the state system implemented by the factory compounds.

integer

points

point cloud

custom

read/write

State_transition_Time

The time at which a particle last changed states, in seconds.

This attribute is set by the State compounds and used by the Get Time in State and Test Time in State compounds. You can also get this attribute and use it to do other things based on when a particle changed state.

scalar

points

point cloud

custom

read/write

StaticFriction

The coefficient of static friction. This attribute is used by the Simulate Rigid Bodies node to calculate particle motion.

When two bodies are in contact and at rest, static friction creates a resistance force that must be overcome by other forces before the bodies start moving. The resistance is along the plane of contact and is proportional to the product of the coefficient and component of force that is pushing the bodies together (e.g., the weight of an object on a sloping surface).

When two bodies are in contact, the coefficient of static friction for their interaction is the product of their respective StaticFriction values.

If this attribute is not defined, the default value used by the Simulate Rigid Bodies node is 0.5.

scalar

points

point cloud

polygon mesh

NURBS surface

NURBS curve

lattice

predefined

read/write

StickLocation

The location that a particle sticks to.

This attribute is set by the Stick compounds when a particle initially sticks to a location.

location

points

point cloud

custom

read/write

StickOffsetMatrix

The offset matrix of a particle from its StickLocation.

The Stick compound applies this matrix to set the particle's final position and orientation each frame.

4x4 matrix

points

point cloud

custom

read/write

StrandAge

The age of a strand in seconds.

This attribute is set and updated by the Generate Strand Trails compound.

array of scalar

points

point cloud

custom

read/write

StrandCenter

Set and used by the Strand compound to control strand deformations.

array of 3D vector

points

point cloud

custom

read/write

StrandColor

The color of shapes along a strand.

Although this attribute does not appear in the list of attributes displayed by the Explore button of Get Data and Set Data property editors, it is understood and used by certain shaders.

If the size of this array does not match StrandPosition, it is ignored.

array of colors

points

point cloud

predefined

read/write

StrandCount

Set and used by the Strand compounds to keep track of the number of segments in a strand.

integer

points

point cloud

custom

read/write

StrandDeform

Whether shapes are lofted along the length of the strand (true) or placed individually at the discrete StrandPosition values (false).

Lofting is supported only for Box, Capsule, Cone, and Cylinder shapes.

Booleans

points

point cloud

predefined

read/write

StrandLength

Set and used by the Strand compounds to keep track of the total length of strands.

scalar

points

point cloud

custom

read/write

StrandOrientation

Used to orient shapes along a strand.

If StrandDeform is false, the orientation is relative to the point cloud's local space. If StrandOrientation is not defined, the base particle's Orientation is used instead.

If StrandDeform is true, StrandOrientation provides an extra rotation that is applied on top of the orientation defined by the strand's tangent and StrandUpVector. The reference for StrandOrientation is established by using the strand's tangent as the Y axis and StrandUpVector as the X axis. If StrandUpVector is not defined, the up-vector is calculated from the camera, which will make the deformations rotate if the camera moves.

If the size of this array does not match StrandPosition, it is ignored.

array of rotations

points

point cloud

predefined

read/write

StrandPosition

The positions of shapes along a strand.

array of 3D vectors

points

point cloud

predefined

read/write

StrandSize

The sizes of shapes along a strand.

If this attribute is not defined, the base particles' Size is used instead.

If the size of this array does not match StrandPosition, it is ignored.

array of scalars

points

point cloud

predefined

read/write

StrandUpVector

Used to establish a reference frame for StrandOrientation if StrandDeform is true. The vector is expressed relative to the point cloud's local space.

The strand tangent defines the Y axis and this attribute represents the X axis in the point cloud's local coordinates.

If this attribute is not defined, the up-vector is calculated from the camera, which will make the deformations rotate if the camera moves.

If the size of this array does not match StrandPosition, it is ignored.

array of 3D vectors

points

point cloud

predefined

read/write

StrandVelocity

Available for compounds to store the velocities of the shapes at the StrandPosition values.

This attribute is not updated by the Simulate Particles or Simulate Rigid Bodies nodes.

If this attribute exists, it is used for rendering motion blur. If this attribute is not defined, the base particle's PointVelocity is used instead.

If the size of this array does not match StrandPosition, it is ignored.

array of 3D vectors

points

point cloud

predefined

read/write

SurfaceGeometricNormal

The normal of the underlying geometry at a location,.

This attribute is available at surface locations only. On polygon meshes, it is the normal of the tesselated triangle and is not interpolated. On NURBS surfaces and curves, it is the exact normal at that location.

3D vectors

n/a

polygon mesh

NURBS surface

NURBS curve

inherent

read-only

Symmetry Indices

The index of the corresponding point across the plane of symmetry.

integer

points

symmetry map

inherent

read/write

UVs

The UV coordinates of a texture projection at a location.

If you get this attribute on a spatial projection, the W value is dropped. If you set this attribute on a spatial projection, the W coordinate is set to 0.

If you get this attribute on a homogeneous (camera) projection, you get the raw, undivided UV values and the distance to the camera q is dropped. If you set this attribute on a homogeneous projection, q is set to 0 and stored in the W coordinate.

2D vector

samples

texture UV coordinates

inherent

read/write

UVs_NonHomogeneous

The non-homogeneous equivalents of the texture UV coordinates at a location in a texture projection.

If you get this attribute on a spatial projection, the W value is dropped. If you get this value on a homogeneous (camera) projection, the values (U/q, V/q) are returned.

2D vector

samples

texture UV coordinates

inherent

read-only

UVWs

The UVW coordinates of samples at a location in a texture projection.

If you get this value on a regular UV projection, the values of (U, V, 0.0) are returned. If you set this attribute on a regular UV projection, the W value is ignored.

If you get or set this value on a homogeneous (camera) projection, the values correspond to (U, V, q) where q is the distance to the camera.

3D vector

samples

texture UV coordinates

inherent

read/write

UVWs_NonHomogeneous

The non-homogeneous equivalents of the stored texture UVW coordinates.

If you get this value on a regular UV projection, the values of (U, V, 0.0) are returned.

If you get this value on a homogeneous (camera) projection, the values of (U/q, V/q, 0) are returned where q is the distance to the camera.

3D vector

samples

texture UV coordinates

inherent

read-only

Volume

The volume of polygon meshes in cubic Softimage units.

scalar

objects

polygon mesh

inherent

read-only

VolumeCloud

Used internally by certain shaders. Setting this attribute in the ICE tree has no effect.

Boolean

objects

point cloud

inherent

read/write

Weights

The values of a weight map.

scalar

points

weight map

inherent

read/write