Houdini 18.0 Nodes TOP nodes

Attribute Array TOP node

Creates and modifies array attributes on work items.

This node provides methods for creating array attributes based on existing attributes or patterns of values.


Work Item Generation

Whether this node generates static or dynamic work items. You should generally leave this set to "Automatic" unless you know the node’s work items can be computed statically, or that they need to be generated dynamically.


This node always creates dynamic work items: it waits until the upstream work items are known, and generates new work items from the upstream work items.


This node always creates static work items: it creates the number of work items it thinks it needs based on the parameters (and any upstream static items) before the network runs.


If the input is static (a static processor, or a partitioner with only static inputs, or a mapper), this node generates static work items, otherwise it generates dynamic work items.

Create When

If you turn this on, the node only creates the attribute below for work items where the given expression evaluates to a non-zero value. For example, to create the attribute only for any work items whose tile_x attribute is greater than 5, turn on Create When and set the expression to @tile_x > 5.

New Attribute Name

Name of the attribute to create.

Existing Name

What to do when there is already an attibute with the name New Attribute Name .

Replace Existing Attribute: Replace the attribute if it already exists.

Update Existing Attribute: Overwrite the existing elements in-place, does not remove unaffected elements.

Append to Existing Attribute: Adds new elements to the end of the existing array.

Prepend to Existing Attribute: Adds new elements to the front of the existing array.

Generate Warning on Type-mismatch: When the existing attribute has a different type, generate a node warning and does not change the attribute.

Generate Error on Type Mis-match: When the existing attribute has a different type, generate a node error.

Create Array From

How the array will be created.

Value Pattern: Enter a Value Pattern to generate the array values.

Array Values: Enter a multi-parm of values.

Attribute Pattern: Match upstream attributes and append their contents to form the new array. The attributes are matched in sorted order.

Existing Array Attribute: Copy values from another array attribute.

Output Files: Copy from Input Files.

Array Type

The type of the array to create in Array Values and Value Pattern mode.

Attribute Pattern

The Pattern used to match attribute names.

Attribute Value Pattern

Enter a Value Pattern to generate the array values.

Attribute Name

The attribute to copy values from in Existing Array Attribute mode.

Copy Values

Which elements to copy from the given attribute.

Take All: Copies all elements.

Take Slice: Copies values based on the start, end and step indicies.

Take First: Copies Count elements from the front of the array.

Take Last: Copies Count elements from the back of the array.

Take Middle: Copies the element at index ceil(N / 2) if N is the length of the array.

Take At Index: Copies the element at the given index.

At Index

The index of the first element to copy, can count from the end by using a negative index.

End Index

If enabled, one past the last element to be copied. If disabled the slice runs to the final element. Can use a negative index to count from the end.


How many elements to skip when taking the slice. 1 means take every element, 2 means skip every other element.


How many elements to copy from the array.

Output File Tag

The file tag to match input Files. The matching files will be copied into the new array.


If enabled the contents of the array will be sorted order.


If enabled the contents of the array will be reversed.

On Index Error

What do do if the node is not able to copy the elements because the given index range is invalid.

Generate Error: Generate a node error.

Generate Warning: Generate a node warning.

See also

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