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.