Prepare to use the Smoke effect
Before you use the Smoke effect, be aware of
these issues:
- Use
the Smoke effect on at most one object at a time.
To apply Smoke to a group of NURBS surfaces,
first convert each surface to polygons and combine the surfaces.
From the Polygons menu set, select
Modify > Convert > NURBS to Polygons,
then choose
Mesh > Combine.
To apply Smoke to a group of polygonal surfaces,
simply combine the surfaces with
Mesh > Combine.
- If
you emit from a NURBS or polygonal object, the size and shape of
the object affects the quality of the smoke. You’ll need to use
an object large enough to generate an adequate smoke area. If you
emit smoke from a curve, avoid using a curve with abrupt changes
in direction.
- It’s
often useful to use the Smoke effect on the same geometry more than once.
By setting options differently with each usage, you can create a
complex look not possible with a single usage. For instance, by
using two emitters with different emission rates and different sprite
sequences, you can create a combination of burning smoke and steaming
smoke.
- If
you want to animate the movement of the smoke around the workspace,
consider using the Smoke effect on a particle object. You can work with
per particle expressions on particle objects, so you have more flexibility
in altering the smoke’s motion.
- You’ll
often need to emit smoke from part of an object rather than from its
entire geometry. In some instances, the part of the object where
you want the smoke won’t have geometry present. A common technique
in such cases is to emit from an invisible geometric object in that
area.
For example, suppose you want to blow smoke
out of the end of a hollow exhaust pipe, but the pipe has no object
where you can conveniently emit the smoke. You can create a disk
of the correct size and shape, position it inside the pipe, and
apply an emitter to the disk. Make the disk invisible by selecting Display
> Hide > Hide Selection.
- If
you create your own smoke images, for instance, with paint software such
as VizPaint or StudioPaint, remember to save the alpha channel (transparency
data) when you create the images.
To
use the Smoke effect
- To
use smoke images supplied with Maya, copy the images Smoke.0 through Smoke.50 from
the following directory on the Maya DVD to the /sourceimages directory of your current
project:
To use your own images, put them in the /sourceimages directory of your current
project.
- Do
one of the following:
- Select
the object or CVs, edit points, vertices, or particles that you
want to emit smoke.
- To
create a positional emitter, deselect all objects.
- Select
Effects > Create Smoke > .
- Set attributes in the Create Smoke Effect
Options window (see
Edit attributes of the Smoke effect)
and click Create.
The Smoke effect creates an emitter, emitted
particle object, expressions, turbulence field, and other fields
needed to make the smoke.
- Play
the animation.
Emitted particles appear as squares in the workspace
because the particles are displayed as the Sprite render type.
Here’s an example with
Shading > Smooth Shade All turned
on.
- Hardware
render the scene to see the smoke.
See Rendering for details.
Edit attributes of the Smoke effect
The following pages explain attributes for tuning
the Smoke effect. The Smoke effect creates several custom attributes
in the emitted particle object it creates. The custom attributes
control a combination of field and emitter attributes to lessen
the settings you would otherwise need to make to tune the smoke.
Attributes in the Create Smoke Effect
Options window
The
following attributes appear in the Create Smoke Effect
Options window when you select
Effects > Create Smoke > . Changes
you make to the options window affect smoke you create after you
make the changes.
You can edit most of these attributes after
you use the Smoke effect by selecting the emitted particle object
and opening the Extra Attributes section of the Attribute
Editor.
Additional tips
You can do the following additional steps to
tune the smoke’s appearance:
- Change
the size and orientation of the smoke by altering the Scale and Rotate values
of the emitted particle object.
- Key
a change in the value of Scale Y to
make the particles appear to move faster or slower.
- Edit
attributes of the sprites. See
Sprites.
- Edit
any expressions created by the Smoke effect. To learn which expressions
are created by the effect, apply Smoke to an object in an otherwise empty
scene. Use the Expression Editor to see the
additions.
- Turn
off the turbulence field by disconnecting
it using the Dynamics Relationship Editor.
- Animate
the emitter to move the smoke in your scene.