You can use the Wind modifier to apply wind effects to spline primitives. The wind force is controlled by a 3D vector field with a main direction force and a second force that runs perpendicular to the main wind force. When setting up the Wind modifier, consider the following:
- Use the Direction attribute to set the main direction of the vector wind. By default, the wind force moves along the X axis.
- Use the Shear Freq and Shear Strength attributes to set wind vectors that run perpendicular to Direction. This way you can generate simple turbulence in the wind force.
- Use the Gust Strength attribute to set the strength of the wind force.
- Add noise to the main Direction and Shear vectors using the Low S and Lo Bias attributes for low frequency noise and Hi S and h Hi Bias for high frequency noise.
Wind Modifier
- Mask
-
Lets you control how the modifier affects primitives in specified areas of the surface. For example, use Mask to load or an expressions or create a Ptex map that masks out the effect of the modifier.
- Stiffness
-
The higher the stiffness the less splines bend in the wind.
- Direction
-
Main vector direction of the wind.
- Const Strength
-
Constant strength of the wind in its main vector direction.
- Gust Strength
-
Maximum strength of the wind component in its main direction (controlled with the Noise locator).
- Shear Strength
-
Maximum strength of the wind component in its secondary direction (perpendicular to the main one).
- Shear Freq
-
Shear frequency (wind component in the transversal direction).
- Seed
-
Randomization seed for the noise generation.
- Pref Noise
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Turning this on can stop unwanted motion in the noise field when working with animated or deforming meshes.
For information about Prefs, see XGen patches.
- Low S
-
Sets the low frequency noise.
- Low Bias
-
Sets the low frequency noise bias.
- Hi S
-
Sets the high frequency noise.
- Hi Bias
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Sets the high frequency noise bias.
- Hi Freq
- Sets a value for the high frequency (Hi S) . The low frequency (Low S) is scaled to be lower than this value.
- Rigid Body
- When on, the CV's of the primitives are locked so they behave as a rigid objects when affected by the wind force.
- Clump
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When on, primitives are treated as clumps by the wind force. For this to work you must create a clumping map such as the one used by a Clumping modifier. See Create point maps for XGen Modifiers.
Loopable Wind
- Loopable
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Loops the Wind Modifier effect between the specified Loop Start Frame and Loop End Frame.
- Loop Start Frame
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Start frame for loopable noise.
- Loop End Frame
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End frame for loopable noise.
- Loop Noise Span
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Sets the noise field units when the wind travels in the loop.