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Synopsis

volumeAxis [-alongAxis float] [-aroundAxis float] [-attenuation float] [-awayFromAxis float] [-awayFromCenter float] [-detailTurbulence float] [-directionX float] [-directionY float] [-directionZ float] [-directionalSpeed float] [-invertAttenuation boolean] [-magnitude float] [-maxDistance linear] [-name string] [-perVertex boolean] [-position linear linear linear] [-turbulence float] [-turbulenceFrequencyX float] [-turbulenceFrequencyY float] [-turbulenceFrequencyZ float] [-turbulenceOffsetX float] [-turbulenceOffsetY float] [-turbulenceOffsetZ float] [-turbulenceSpeed float] selectionList

volumeAxis is undoable, queryable, and editable.

A volume axis field can push particles in four directions, defined with respect to a volume: along the axis, away from the axis or center, around the axis, and in a user-specified direction. These are analogous to the emission speed controls of volume emitters. The volume axis field also contains a wind turbulence model (different from the turbulence field) that simulates an evolving flow of liquid or gas. The turbulence has a build in animation that is driven by a connection to a time node.

The transform is the associated dependency node. Use connectDynamic to cause the field to affect a dynamic object.

If fields are created, this command returns the names of each of the fields. If a field was queried, the results of the query are returned. If a field was edited, the field name is returned.

If object names are provided or the active selection list is non-empty, the command creates a field for every object in the list and calls addDynamic to add it to the object. If the list is empty, the command defaults to -pos 0 0 0.

Setting the -pos flag with objects named on the command line is an error.

Return value

string

In query mode, return type is based on queried flag.

Flags

alongAxis, aroundAxis, attenuation, awayFromAxis, awayFromCenter, detailTurbulence, directionX, directionY, directionZ, directionalSpeed, invertAttenuation, magnitude, maxDistance, name, perVertex, position, turbulence, turbulenceFrequencyX, turbulenceFrequencyY, turbulenceFrequencyZ, turbulenceOffsetX, turbulenceOffsetY, turbulenceOffsetZ, turbulenceSpeed
Long name (short name) Argument types Properties
-alongAxis(-alx) float queryedit
Initial velocity multiplier in the direction along the central axis of the volume. See the diagrams in the documentation.
-aroundAxis(-arx) float queryedit
Initial velocity multiplier in the direction around the central axis of the volume. See the diagrams in the documentation.
-attenuation(-att) float queryedit
Attentuation rate of field with distance. For sphere volumes, distance is computed from the center of the sphere. For cone, cylinder, and cube volumes, it is computed from the vertical axis of the volume. For torus volumes, it is computed from the ring in the middle of the solid portion of the torus.
-awayFromAxis(-afx) float queryedit
Initial velocity multiplier in the direction away from the central axis of the volume. See the diagrams in the documentation. Used only with the cylinder, cone, and torus volumes.
-awayFromCenter(-afc) float queryedit
Initial velocity multiplier in the direction away from the center point of a cube or sphere volume. Used only with the cube and sphere volumes.
-detailTurbulence(-dtr) float queryedit
The relative intensity of a second higher frequency turbulence. This can be used to create fine features in large scale flows. Both the speed and the frequency on this second turbulence are higher than the primary turbulence. When the detailTurbulence is non-zero the simulation may run a bit slower, due to the computation of a second turbulence.
-directionX(-dx) float queryedit
x-component of force direction. Used with directional speed.
-directionY(-dy) float queryedit
y-component of force direction. Used with directional speed.
-directionZ(-dz) float queryedit
z-component of force direction. Used with directional speed.
-directionalSpeed(-drs) float queryedit
Adds a component of speed in the direction specified by the directionX, Y, and Z attributes.
-invertAttenuation(-ia) boolean queryedit
If this attribute is FALSE, the default, then the attenuation makes the field's effect decrease as the affected point is further from the volume's axis and closer to its edge. If the is set to TRUE, then the effect of the field increases in this case, making the full effect of the field felt at the volume's edge.
-magnitude(-m) float queryedit
Strength of field.
-maxDistance(-mxd) linear queryedit
Maximum distance at which field is exerted. A zero or negative value will turn off the field effect completely. For sphere volumes, distance is computed from the center of the sphere. For cone, cylinder, and cube volumes, it is computed from the vertical axis of the volume. For torus volumes, it is computed from the ring in the middle of the solid portion of the torus.
-name(-n) string queryedit
name of field
-perVertex(-pv) boolean queryedit
No effect for this type of field.
-position(-pos) linear linear linear queryeditmultiuse
Position in space where you want to place the volume.
-turbulence(-trb) float queryedit
Adds a force simulating a turbulent wind that evolves over time.
-turbulenceFrequencyX(-tfx) float queryedit
The repeats of the turbulence function in X.
-turbulenceFrequencyY(-tfy) float queryedit
The repeats of the turbulence function in Y.
-turbulenceFrequencyZ(-tfz) float queryedit
The repeats of the turbulence function in Z.
-turbulenceOffsetX(-tox) float queryedit
The translation of the turbulence function in X.
-turbulenceOffsetY(-toy) float queryedit
The translation of the turbulence function in Y.
-turbulenceOffsetZ(-toz) float queryedit
The translation of the turbulence function in Z.
-turbulenceSpeed(-trs) float queryedit
The rate of change of the turbulence over time. The turbulence loops seamlessly every 1.0/turbulenceSpeed seconds. To animate this rate attach a new time node to the time input on the volumeAxisNode then animate the time value on the time node.

Flag can appear in Create mode of command Flag can appear in Edit mode of command
Flag can appear in Query mode of command Flag can be used more than once in a command.

MEL examples

volumeAxis -pos 0 0 0 -afc 1.0 -afx 2.0 -arx 3.0 -alx 4.0 -drs 6.0;

// Creates a volume axis field with the following attribute values:
// awayFromCenter = 1.0, awayFromAxis = 2.0, aroundAxis = 3.0, alongAxis = 4.0,
// directionalSpeed = 6.0.