Houdini 20.0 Nodes VOP nodes

Undulatus VOP node

Generates a 2D, wave like cloud pattern.

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Since 20.0


Translated from Latin meaning undulated, they appear as cloud heaps arranged in parallel rows or wavy undulations in the underside of a cloud.


Use the coverage input on this VOP to mask this node’s effect.


Undulatus Pattern

Element Size

Uniform scale of elements in the noise.


Offsets the direction of the wave patterns along their facing direction. Use this to move patterns to a desirable location. With each increased unit value, each wave takes the place of its forward pattern.

Relative Thickness

Controls the relative width of each wave. Lower the value to create thinner trails.


Smooths the front side of the wave patterns.

Mirror Pattern

If mirroring of ramps is turned on, the ramps will alternate in slope forming tent functions.

Distort Waves

Distort Wave Pattern

Distorts the otherwise simple ramp patterns into a wave like pattern using spacial noise.


Controls the effect of the distortion. Large values will create larger distortion, but might create unrealistic looking cloud patterns. Similarly, lowering the value too much reveals the underlying simplistic ramp pattern.

Element Size Scale

Uniform scale of elements in the distortion noise. This scale is relative to Element Size which controls the overall pattern size.


Offset within the evaluated noise field (added to each axis). If you have the general noise effect you want, but want to get a different set of values for a different look, try changing the offset.

You can animate the noise using an expression such as $T * 0.25 here. This is faster to compute than Animate Noise, but gives the visual effect of “panning” across the noise field, which may or may not be acceptable.

Click the Per Component button for separate additional offsets along each axis.


When you turn on the Per Component button, you are able to add a separate offset along each axis.


Max Octaves

The number of iterations of distortion to add to the output of the basic noise. The more iterations you add, the more “detailed” the output. Note that the output may have fewer octaves than this parameter (that is, increasing the parameter will eventually stop adding detail), because the node eventually stops when there’s no more room to add more detail in the output.


The frequency increment between iterations of fractal noise added to the basic output. Note that you can use a negative value.


The scale increment between iterations of fractal noise added to the basic output. The higher the value the larger the “jaggies” added to the output. You can use a negative value for roughness.



Controls how much the noise is distorted in the direction of decreasing noise values if Distortion is greater than 1, and in the direction of increasing noise values if Distortion is less than 1. When worley details are added to the noise pattern, the effect of distortion are largely diminished.

Distortion with a value of 1:

Distortion with a value of -1:


How much to stretch the noise in each direction. The advantage of using this instead of Element Size is that it preserves some details unstretched, making the stretched noise pattern more natural looking.

Comparing Element Scale of 3 (left) to Stretch value of 3 (right) along the X-axis:


Warps the generated noise such that the noise pattern is bending or hanging towards the given droop direction.

Noise pattern without (left) and with droop applied (right):

Droop Direction

The direction in which the noise is warped.



Rotates the pattern around the up vector (given by Up Vector). Use this to control which direction the pattern is facing.

Up Vector

The normal vector of the 2D plane used to generate the noise.

See also

VOP nodes