Houdini 20.0 Nodes VOP nodes

Anti-Aliased Ramp Parameter VOP node

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Since 12.0

This node may be used to create a ramp interface on a material, similar to the Ramp Parameter VOP, but with built-in filtering and range extension.

However, Houdini does not treat this node specially as it does the Parameter nodes, so to promote the UI for this node, you must choose Promote Interface ▸ UI + Links + Inputs to trigger scripts on the node to promote and create parameters up on the parent node.

This node combines the functionality of a Ramp Parameter VOP and a Ramp filter VOP.


Filter width override

Controls the size of the anti-aliasing filter. In some contexts the node can choose a proper width based on the available global variables. In other contexts, such as SOPs, the width will default to 0. If you connect a node to the input, the input value will be used even if the node can deduce a default width automatically.

Filter scale

The amount of anti-alias blurring to add to the output value.



When this checkbox is off, the node has no effect. May be useful for debugging.

Unique Ramp Name

A name for the ramp parameter to be generated on the parent node.


The label to use for the generated ramp parameter.

Disable when

Use this string as the “disable when” value for the ramp parameter created on the parent node.

Callback script

Use this string as the “callback script” value for the ramp parameter created on the parent node.


Use this string as the tooltip for the ramp parameter created on the parent node.

Ramp type

The type of ramp to display when the user interface is promoted.


The color/coordinate space in which the ramp operates.


The gamma to apply to the ramp output.


The range of values the ramp applies to. For example, when the range is 0 to 1, the leftmost value on the ramp represents 0, and the rightmost value on the ramp represents 1. The node computes the results of inputs outside this range according to the “extend” parameters below.

Extend left/right

How to compute the result for inputs below/above the ramp’s range.


Returns the value at the nearest end of the ramp (for example, if the ramp’s range is 0-1, and the input is -10, it will return the ramp value for 0).


Repeats the ramp continuously outside the range.


Like “Cycle”, but starts each cycle relative to the end value of the previous cycle.


Cycles before/after the range are mirror images (reversed) of one another. The first cycle is not mirrored.


Extends a line using the slope at the beginning/end of the ramp range.


The type of filtering to use. The default is “Point” meaning no filtering.


When Filter is “Box” or “Gaussian”, controls the scale of the filter effect.

See also

VOP nodes