Features ›› Procedural Nodes ›› Noise Nodes ›› FBM ››
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FBM+ by Jens Kafitz

FBM+ is a different implementation of Fractal Brownian Motion with an algorithm taken from the book Advanced Renderman for closer

conformity with Renderman based pipelines. It features some additional options and modifications giving slightly different results and more control

than Brownian Noise.




The two colors that make up the final look of the procedural


Size of fractal features on your model

Understanding Noise terminology

For some background information on the terms below please refer to

Understanding some basic noise terms

Describes the level of detail of the noise. Detail is created by encapsulating the modifiers below into a loop and

running it multiple times incrementing the values from loop to loop.

Controls the size of the secondary fine details.

Offsets Size and Lacunarity against each other. High offset Values will result in a very detailed but spotted result,

with very few large features.

Raising Offset on FBM

A random start value for your fractal.

Changing the seed changes the overall look of your fractal while the general feature look stays the same,

allowing for quick variation with a general look theme.


Amplitude affects the length and amount of fine detail the Lacunarity is contributing to the base pattern

Raising Amplitude on FBM

The amount to multiply the noise's amplitude by, contrasting the noise..

A Gain of 0.0 will result in the value defined under Baseline.

Baseline is used to bias your Noise result towards color a or color b.

It will multiply a value with the generated noise (before thresholding) then add the same value:

(Noise * Baseline) + Baseline.

When Baseline is set to 0.0 no multiplication or addition is done effectively disabling the behavior.

Different Baseline Values

When generating a Noise, values are often generated from -1.0 to 1.0.

Absolute Values will convert any negative Value to a positive one giving more 'solid' noise results.

Clamps the noise calculation to a 0-1 range.

Color A/B are applied after the Clamping, so you can still set values above 1 if you choose to

however by clamping the Noise calculation the color mixing between the two colors works more


In general this should be left on.

Inverts the result of the noise. Inversion is done before color A and B are applied.


Defines the Value at which point incoming colors/values go to black (incoming values to the left of the set slider value)

or white (incoming values to the right of the set slider value).

Used to visually soften the thresholding, it defines the Upper+Lower Bound of the Threshold

For example with a Threshold Value set to 0.5 and a Edge Value of 0.1, incoming values lower than 0.4

will be black and incoming values higher than 0.6 will be white. Between 0.4 and 0.6 will be a soft gradient.


By default this procedural is generated in 3D World Space. This results in a seamless noise across UV seams.

By turning on UV Space the procedural is generated based on your UVs, resulting in seams between UV tiles/UDIM & uv shells.

Utilizing Transform Controls such as Scale (see below) you can apply a non-uniform transform to the procedural

to make use of specific UV layouts

Transform Scale

Will apply a scale along X,Y or Z to your noise. This is useful for creating patterns like woodgrain, drips etc.

When UV Space is turned on Scale Z is ignored.

Transform Rotate

Will apply a rotation in X,Y or Z to your noise. When UV Space is turned on Rotate X & Rotate Y are ignored

and rotation is done around the center of each UV Tile/UDIM using Rotate Z.

Transform Translate

Will apply an offset in X,Y or Z to your noise. When UV Space is turned on Translate Z is ignored.

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