Houdini 21.0 Nodes Copernicus nodes

Bubble Noise Copernicus node

Generates bubble noise.

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Since 21.0

This node generates a bubbly noise pattern. This node is similar to when the Fractal Noise COP is the Torus Noise Type, but each level of the fractal is distorted (which causes compression and expansion).

Note

This is a periodic noise due to the nature of the underlying torus noise.

For example, use this node to create billowy clouds or sharp caustics.

Parameters

Bubble Noise

Amplitude

The amount by which to multiply the noise, which the node applies before the Center adjustment.

For example, a value of 0.5 makes a pixel value of 0.5 become 0.25.

Note

Layers can store negative numbers and values above 1, so this may result in out-of-bounds values. Use the Post Processing options to clamp the output.

Center

The center of the output noise range, which offsets the pixel values.

For example, a value of 0.5 makes a pixel value of 0.5 become 1.

Element Size

The size (in image coordinates) of the basic element of the noise. You can turn on the Per-Component Controls button to adjust this further using the Element Scale parameter.

Element Scale

When the Per-Component Controls button is on, this is the per-axis scaling of the element size for anistropic noise.

Phase

The location of the noise in four-dimensional space, which lets you smoothly pick different seeds. Torus noise works by sampling a flat torus in a four-dimensional space.

Offset

The amount to offset the entire noise function in image coordinates.

Tile Size

The size of a single tile of noise. The noise periodically repeats in this size. The size is in image coordinates, so the default is for the entire default canoncial image. If you have a non-square image, this should match the aspect ratio.

Fractal

Max Octaves

The amount of times to scale add together the noise.

Lacunarity

The amount to scale the noise for each iteration, which is rounded to an integer value for periodic noise.

Roughness

The amount to scale the amplitude of each successive noise.

Warping

Distortion

The amount to distort the noise in the direction of decreasing noise values (when greater than 1) or increasing noise values (when less than 1).

Stretch

The amount to stretch the noise in each direction in image coordinates.

Note

Use this parameter instead of Element Size to preserve some details unstretched, which makes the stretched noise pattern look more natural.

Droop

The amount to warp the generated noise pattern so it bends or hangs towards the Droop Direction.

Droop Direction

When Droop is on, this is the direction in image coordinates in which to warp the noise.

Fold

Remaps the values between -1 and 1 and flips values below 0 to the positive range. For example, a pixel value of -2 becomes 2. This makes all valleys become peaks.

Note

The node remaps the values during the noise evaluation. This is different from applying an absolute function afterwards like some other noise nodes (Fractal Noise for example).

Post Processing

Note

The node applies the post-processing operations in the order they're listed.

Complement

Sets the pixel value x to 1 - x.

Note

This method works for values in the 0 to 1 range. For images outside of this range, using Complement results in negative or out of range values.

Bias

The amount to pull the medium grey values (around 0.5) towards zero (if Bias is less than 1) or one (if Bias is greater than 1). A bias value of 0.5 doesn’t affect the values.

Gain

The amount to pull the medium grey values (around 0.5) together, while values around 0 and 1 are pulled apart. A gain value of 0.5 doesn’t affect the noise values.

Gamma

The overall gamma of the generated noise. Values greater than 1 increase the range of values in originally bright areas, which darkens the noise. Values less than 1 stretch out the range of values for originally dark areas, which increases the overall brightness of the noise.

Contrast

The amount to expand or shrink the overall range of tonal values. Each noise value is pushed towards (if Contrast is less than 1) or away from (if Contrast is greater than 1) medium grey values (around 0.5).

Note

This is not the same as Noise Contrast, which appears in some noise nodes and applies contrast during the noise function.

Clamp Minimum

Clamps values below the specified threshold.

Clamp Maximum

Clamps values exceeding the specified threshold.

Inputs

size_ref

A representative layer that determines the size of the output image and controls the metadata.

pos

An optional UV layer with a value that’s used instead of the pixel’s image coordinates for the noise.

Outputs

noise

The computed noise.

See also

Copernicus nodes