You can use Maya Fields to
animate the motion of nParticles and create the effect of nParticles
flowing around obstacles, as well as creating pluming smoke, swirling
tornadoes, and rocket exhaust. For a smoke simulation, you can add
a Volume Axis field to the scene
to create turbulence and swirling effects in the smoke as it rises
through the air.
Maya Fields are
not part of an nParticle object's Nucleus system and therefore you
may need to compensate for the force of Nucleus Gravity and Wind by
increasing or decreasing the field's magnitude. Depending on the
effect you are creating, you can also turn on Ignore
Solver Gravity or Ignore Solver Wind on
the nParticleShape node so that your nParticle object is only affected
by Maya Fields. For more information about
Maya fields see the Dynamics guide.
To create a Volume Axis field
- In the Outliner,
select nParticle_Smoke, then add a Volume
Axis field by selecting Fields > Volume
Axis > .
Axis Options window appears.
- In the Volume Axis Options window, select Edit
> Reset Settings.
- In Volume axis field name,
- Set the following Volume
Axis field settings:
- Volume Shape: Cube
- Away From Center:
- Directional Speed:
X to 0 and Y to 1.0.
- Turbulence Speed: 0.157
- Click Create.
A Field_Smoke1 node appears
in the Attribute Editor and in the Outliner.
Axis field is placed at the scene origin by default.
You must reposition the field so that the emitted nParticles travel
through the volume.
To position the field in the path of
the emitted nParticles
- In the Outliner,
select Field_Smoke1 and open the Channel
Box by clicking .
- In the Channel Box under Field_Smoke1,
set the following:
- ScaleX: 10
- ScaleY: 10
- ScaleZ: 10
- Play the simulation.
The field creates turbulence
in the nParticle smoke as it rises.
However, to create the
effect of the smoke curling and dissipating, you need to adjust
the field and nParticle attributes further. For example, the emitted
nParticles have too much velocity for the field to influence their
behavior. You will make these adjustments in the next section.