Houdini 18.5 Nodes TOP nodes

Attribute Array TOP node

Creates and modifies array attributes on work items.

On this page
Since 18.0

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

Parameters

Generate When

Determines when this node will generate work items. You should generally leave this set to "Automatic" unless you know the node requires a specific generation mode, or that the work items need to be generated dynamically.

All Upstream Items are Generated

This node will generate work items once all of the input nodes have generated their work items.

All Upstream Items are Cooked

This node will generate work items once all of the input nodes have cooked their work items.

Each Upstream Item is Cooked

This node will generate work items each time a work item in an input node is cooked.

Automatic

The generation mode is selected based on the generation mode of the input nodes. If any of the input nodes are generating work items when their inputs cook, this node will be set to Each Upstream Item is Cooked. Otherwise, it will be set to All Upstream Items are Generated.

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 attribute 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.

Step

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

Count

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.

Sorted

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

Reversed

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.

Examples

CreateArray Example for Attribute Array TOP node

This example demonstrates how to create an array attribute.

ModifyArray Example for Attribute Array TOP node

This example demonstrates how to modify or update an existing array attribute.

See also

TOP nodes