Auto Resize
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Maya Fluid Effects now includes
an Auto Resize feature. Auto
Resize dynamically resizes 2D and 3D fluid containers
when the density near the edges of the fluid reaches the set Auto
Resize Threshold value. With Auto Resize on, Maya
allows the container to only extend to regions with density, rather than
keeping the fixed resolution and offset that the grid started out
with. The smaller simulation region increases simulation speed,
reduces rendered times, uses less memory, and results in smaller fluid
cache files.
Auto Resize works
well with fluid effects that move, such as a missile vapor trail
or the rolling smoke of an explosion, as it keeps the fluid container
relatively small.
 Watch: Fluids Auto Resize
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Self Attraction and Repulsion
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Fluid Effects now includes Self
Attraction and Repulsion attributes that generate attractive
and repulsive forces between the voxels in 2D and 3D fluid containers.
Using Self Attraction and Repulsion attributes, you
can specify whether the forces use density or temperature grid values
as well as control the strength of the attraction and repulsion
force.
You can use Self Attraction
and Repulsion to create effects such as swirling gas
clouds and galaxies that contract and expand. Using a strong self
repulsion force, you can simulate rapidly expanding gases to create
the look of realistic explosion flashes.
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New Dynamic Simulation
attributes
New Dynamic
Simulation attributes improve the quality of fluid simulations.
The new attributes include
the following:
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Forward Advection
Forward
Advection is a new method that you can use for calculating Density, Temperature, and Fuel grids. When
on, these grids are solved using a mass conserving forward propagation technique
that pushes density forward through the grid. Fluid effects solved using Forward
Advection can produce fewer artifacts when the High
Detail Solve option is used, and results in less diffusion
than the default solve method. Forward Advection can
also resolve instances where density remains static in voxels.
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Substeps
Use Substeps to
specify the number of times the solver performs calculations per
frame. Substeps are useful for improving
the stability and simulation results of fast-moving fluids, fluids
with high density grids, and when the High Detail Solve option
is used.
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Output mesh per-vertex
shading attributes
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You can now generate
per-vertex color, opacity, and incandescence data when you convert
your fluid object to a polygon mesh. When on, Color
Per Vertex, Opacity Per Vertex,
and Incandescence Per Vertex generate
per-vertex data which is derived from the fluid object's color,
opacity, and incandescence values. The output mesh per-vertex data
is color set data that can be applied to the polygon object like
other color set data.
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Velocity Per Vertex for
motion blur
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You can now create motion blur
when you render fluid output meshes. A new Velocity
Per Vertex attribute generates velocity per vertex data
when a fluid object is converted to an output mesh. When you render
your fluid output mesh using mental ray for Maya, velocity per-vertex
data generates motion blur in the rendered output.
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Uvw Per Vertex
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You can now generate
a UVW coordinate system for your fluid output meshes. A new Uvw
Per Vertex attribute outputs UVW coordinates when a fluid
object is converted to an output mesh. You can use the Uvw per-vertex
data to assign textures to fluid output meshes.
You can use the UV Texture
Editor to modify the output mesh UVs like any other polygon
surface.
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Fluids Lighting
A number of new Lighting attributes
have been added to Fluid Effects that let you preview the lighting
and shadowing of your fluid in the workspace before rendering. There
are now more internal lights, including point, directional, and
ambient lights, that you can use to light your fluid effect. Using
internal lighting decreases fluid render times. See
Lighting fluids with internal lights.
Watch: New Fluids internal lighting attributes
New fluid lighting features
include the following attributes:
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Shadow Diffusion
Controls the softness
of the fluid's internal shadow, simulating local light scattering. Shadow Diffusion can
only be seen in the workspace not in a rendered fluid. To use Shadow
Diffusion effects in your finalized fluid, you can use Playblast to
output simulated frames.
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Light Type
Use Light Type to
select the type of internal light you want to use with the fluid
when displaying it in the workspace. You can now select an internal diagonal,
directional, or point light. If Real Lights is off,
the selected internal light is used to light the fluid for rendering.
The internal point light
also includes a Point Light Decay attributes
that let you control how quickly the light's intensity decreases
with distance.
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Light Brightness and Light
Color
You can use Light Brightness and Light
Color to set the intensity and color of the selected
internal light. Light Brightness and Light
Color are similar to the intensity and color attributes
that are used with scene lights.
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Ambient lighting
Fluid Effects now includes ambient
lighting which you can preview in the workspace before rendering. Using
ambient light attributes, you can control the intensity, color,
and diffusion of the ambient light.
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New Dynamic Simulation
attributes
New Contents
Details attributes let you add more detail and turbulence
to your fluid effects.
These new attributes
include the following:
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Noise
Density, Temperature,
and Velocity now include a Noise attribute
that randomizes density, temperature, and velocity grid values.
You can use Noise to create turbulence
as well as to add detail to a fluid effect.
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Tension
Density and Temperature now
include a Tension attribute that lets
you smooth ranges of density and temperature into round shapes,
making the density and temperature boundaries more defined in the fluid.
You can use Tension to create effects that are
similar to the effect of surface tension in liquids.
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Gradient Force
Density now includes
a Gradient Force attribute that
applies attractive and repulsive forces along the direction of the
density gradient. Positive Gradient Force values
push in the direction of increasing density, producing an attractive force.
Negative values push density away from itself, producing a repelling
force.
Gradient Force is
similar to Self Attraction and Repulsion,
but the effect of Gradient Force is localized
to the adjacent voxels and takes less time to calculate than Self
Attraction and Repulsion.
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Boundary Draw improvements
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The Outline option
for the Boundary Draw attribute has
been improved on 2D fluid containers. A dotted line displayed around
the container indicates the potential volume of the 2D fluid.
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Emit fluids from nParticles
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You can now emit fluid
from nParticle objects using Emit from Object.
To control the fluid emission rate, you can either use fluid emitter
attributes, or you can use nParticle per-particle rate and per-particle
radius attributes.
For example, you can
use a per-particle ramp or an expression to control the radius of
fluid emission based on the per-particle radius of nParticles. You
can also emit fluid from Maya classic particles.
Emitting fluid from nParticles lets
you combine fluid and nParticle effects in the same simulation.
This provides better control over smoke, fire, dust, or debris clouds
that result from nParticle collisions and explosions.
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New fluid emitter attributes
Maya 2011 includes the
following new fluid emitter attributes:
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Rate (Percent)
A new Rate
(Percent) attributes lets you scale the individual emission
rates of all fluid grids, including Density, Heat,
and Fuel with one attribute. Rate
(Percent) sets fluid emission rate as a percent.
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Emission method
New emission methods
for Density, Heat,
and Fuel let you specify how contents
are emitted into fluids. The default Add method adds
contents using a continuous emission rate. This is the same emission method
used by fluids in previous versions of Maya.
A new Replace emission
method lets you specify the total amount of contents emitted in
the fluid. It can be used to obtain specific amounts of density, heat,
and fuel without needing to reset the fluid’s initial state from
an advanced frame. This is useful for quickly simulating effects
such as rising heat and wind tunnels.
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Emission maps
There are now emission
maps for Density, Heat,
and Fuel. Using the emission map
attributes, you can map a 2D texture to control emitted density, temperature,
and fuel. Texturing the emission is now supported.
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Motion Streak
When on, Motion Streak smooths
emission stamps into a continuous fluid streak. Motion
Streak is most useful for effects with fast moving emitters,
which can cause emission stamping.
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Keep Voxels Square
Use Keep
Voxels Square to set a fluid container's resolution based
on the fluid Resolution and Size values
while maintaining square voxels in the local space of the fluid.
Square voxels can provide better fluid simulation and rendering
results.
When Auto
Resize is on, voxels are kept square by default.
Base Resolution
When Keep
Voxels Square is on, you can use Base
Resolution to simultaneously set the X, Y, and Z Resolution values
of your fluid container.
Texture Rotate
A new Texture
Rotate attribute lets you rotate the fluid's built-in
texture.
Normalized Dropoff
A new Normalized
Dropoff attribute for volume emitters is now fixed relative
to the emitter’s scale, rather than to Worldspace. This ensures
that fluid simulations remain consistent if the fluid container
and emitter are scaled together. It also improves Fluid Dropoff for Cube volume
emitters by using a smooth dropoff towards the volume boundaries.
In previous versions of Maya, a cylindrical shaped dropoff is used
with Cube volume emitters.
Use Distance
A new Use
Distance attribute lets you use Min
Distance and Max Distance with Surface and Curve emitters.
In previous versions of Maya, to use Min Distance and Max
Distance with Surface and Curve emitters, Min
Distance has to be set to a value other than 0. You can
now set Min Distance to 0 for Surface and Curve emitters.
Emission Speed Attributes
A number of new Emission
Speed Attributes let you control speed and velocity emission
for all emitter types. For example, you can adjust emitted speed
along the tangent of a Curve emitter or along the axis of a Volume
emitter.
High Quality Solve improvements
Fluid simulations solved
with the High Quality Solve option are
now more stable and have fewer artifacts when Forward
Advection and Substeps are
used.
