Turbulent Noise effect


Contents [Hide]



The Turbulent Noise effect uses Perlin noise to create grayscale noise that you can use for organic-looking backgrounds, displacement maps, and textures, or to simulate things like clouds, fire, lava, steam, flowing water, or vapor.

The Turbulent Noise effect is essentially a modern, higher-performance implementation of the Fractal Noise effect. The Turbulent Noise effect takes less time to render, and it’s easier to use for creating smooth animations. The Turbulent Noise effect also more accurately models turbulent systems, with smaller noise features moving more quickly than larger noise features. The primary reason to use the Fractal Noise effect instead of the Turbulent Noise effect is for the creation of looping animations, since the Turbulent Noise effect doesn’t have Cycle controls.

Note: Because the controls for the two effects are nearly identical, you can use most instructions and tutorials created for the Fractal Noise effect to instead guide your use of the Turbulent Noise effect. (See Fractal Noise effect.)

The Evolution controls create subtle changes in the shape of the noise. Animating these controls results in smooth changes of the noise over time, creating results that resemble, for example, passing clouds or flowing water.

This effect works with 8-bpc, 16-bpc, and 32-bpc color.

Controls

Fractal Type
The fractal noise is created by generating a grid of random numbers for each noise layer. The Complexity setting specifies the number of noise layers. The Fractal Type setting determines the characteristics of this grid.

Noise Type
The type of interpolation to use between the random values in the noise grid.

Invert
Inverts the noise. Black areas become white, and white areas become black.

Contrast
The default value is 100. Higher values create larger, more sharply defined areas of black and white in the noise, generally revealing less subtle detail. Lower values result in more areas of gray, softening or muting the noise.

Overflow
Remaps color values that fall outside the range of 0–1.0, using one of the following options:
Clip
Remaps values so that any value above 1.0 is displayed as pure white, and any value below 0 is displayed as pure black. The Contrast value influences how much of the image falls outside this range. Higher values result in a mostly black and/or white image with less gray area. Therefore, higher contrast settings display less subtle detail. When used as a luma matte, the layer has sharper, better-defined areas of transparency.

Soft Clamp
Remaps values on an infinite curve so that all values stay in the range. This option reduces contrast and makes noise appear gray with few areas of pure black or pure white. When used as a luma matte, the layer contains subtle areas of transparency.

Wrap Back
Remaps triangularly, so that values above 1.0 or below 0 fall back into the range. This option reveals subtle detail when Contrast is set above 100. When used as a luma matte, the layer reveals more detailed textured areas of transparency.

Allow HDR Results
No remapping is performed. Values outside the range of 0-1.0 are preserved.

Transform
Settings to rotate, scale, and position the noise layers. The layers appear as if they are at different depths if you select Perspective Offset.

Complexity
The number of noise layers that are combined (according to the Sub Settings) to create the noise. Increasing this number increases the apparent depth and amount of detail in the noise.
Note: Increasing Complexity results in longer rendering times. If appropriate, try reducing the Size rather than increasing Complexity to achieve similar results and avoid longer rendering. A trick to increase apparent complexity without increasing rendering time is to use a negative or very high Contrast or Brightness setting and choose Wrap Back for Overflow.

Sub Settings
The noise is generated by combining layers of noise. The Sub Settings control how this combination occurs and how the properties of the noise layers are offset from one another. Scaling successive layers down creates finer details.
Sub Influence
How much influence each successive layer has on the combined noise. At 100%, all iterations have the same amount of influence. At 50%, each iteration has half as much influence as the previous iteration. A value of 0% makes the effect appear exactly as if Complexity is 1.

Sub Scaling
The scale percentage of a noise layer relative to the previous noise layer.

Evolution
Uses progressive revolutions that continue to change the image with each added revolution. This method is unlike typical revolutions that refer to a setting on the dial control for which the result is the same for every multiple of 360°. For Evolution, the appearance at 0° is different from the appearance at 1 revolution, which is different from the appearance at 2 revolutions, and so on.

You can specify how much the noise evolves over a period of time by animating Evolution. The more revolutions within a given amount of time, the more rapidly the noise changes. Large changes in the Evolution value over a short period of time may result in flashing.

Evolution Options
 
Turbulence Factor
The amount by which the speed of smaller noise features differs from the speed of larger noise features. A value of 0 makes the movement of the noise resemble the noise generated by the Fractal Noise effect, in which smaller noise features move at the same speed as larger noise features. A larger value makes the multiple layers of noise appear to roil in a manner more like that of natural turbulence in a fluid.

Random Seed
Sets a random value from which to generate the noise. Animating the Random Seed property results in flashing from one set of noise to another (within that fractal type), which is usually not the result that you want. For smooth animation of noise, animate the Evolution property.

You can easily create new noise animations by reusing previously created Evolution cycles and changing only the Random Seed value. Using a new Random Seed value alters the noise pattern without disturbing the Evolution animation.

Opacity
The opacity of the noise.

Blending Mode
The blending operation between the noise and the original image. These blending modes are identical to the ones in the Modes column in the Timeline panel, with the following exceptions:
None
Renders the fractal noise only and does not composite on the original layer.

Hue
Renders the fractal noise as hue values instead of grayscale. The Saturation and Lightness of the original layer are maintained. If the original layer is grayscale, nothing happens.

Saturation
Renders the fractal noise as saturation values instead of grayscale. The Hue and Lightness of the original layer are maintained. If the original layer is grayscale, nothing happens.

For a description of each blending mode, see Blending mode reference.