Houdini 20.5 Nodes TOP nodes

Block End Feedback TOP node

Ends a feedback loop. TOP nodes within the block execute serially, optionally looping for each incoming work item.

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Since 17.5

This node must come after a corresponding Block Begin Feedback node (with zero or more TOP nodes between them inside the “block”).

This node is a partitioner, and will always create one partition for each work item in the corresponding Block Begin node.

See Feedback Loops for general information on how to use this node.

Parameters

Block Begin Path

Node path of the Block Begin Feedback node this node pairs with.

Merge Operations

Defines the number of attribute merge operations to perform on the partitioner node. The operations are used to merge attributes from work items in the partition onto the partition itself. Operations are performed in descending order. Attributes are merged using the first operation with a pattern that matches the attribute.

Apply Operation

Specifies the operation to perform to merge incoming attributes onto the partition. Each operation only applies only to the subset of attributes matched using the corresponding To Attributes parameter.

The following operations are available:

Ignore

Matching attributes are ignored and will not appear on the partition.

First Value

The value of each matching attribute on the first work item in the partition is kept, and values on subsequent work items are ignored

Last Value

The value of each matching attribute on the last work item in the partition is kept.

Unique Values

The unique values for each matching attribute are merged into an array. Duplicate values are discarded.

Append to Array

The values for each matching attribute are appended to an array for that attribute. All attribute values from all work items are kept.

Minimum

The minimum value for each matching attribute is kept.

Maximum

The maximum value for each matching attribute is kept.

Sum

The sum of the values in each matching attribute is stored on the partition.

Average

The average value of each matching attribute is stored on the partition.

Mode

The most common value in each matching attribute is kept.

Median

The middle value in each matching attribute is kept.

Sorted

The values for each matching attribute are merged into a sorted array.

SortedUnique

Attribute values across all work items are merged into a sorted array, and unique values are kept.

To Attributes

Specifies which attributes the corresponding Apply Operation parameter should apply to. This field can use the Attribute Pattern Syntax to specify multiple attributes.

Preserve Arrays

When on, the merge operation preserves the original array size of the incoming attributes. The merged array size is determined by the first value found across the input work items. When off, the partitioner flattens the incoming array attributes into a single sequence of values (a single scalar value) and performs the merge operation across all values.

Examples

NestedLoop Example for Block End Feedback TOP node

This example demonstrates how to create a nested feedback loop.

See also

TOP nodes