Houdini 18.0 Nodes TOP nodes

Partition by Range TOP node

Partition work items based on range values

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Parameters

Use Dynamic Partitioning

When on, the partitioner waits for all input work items to be generated before partitioning them. If the input work items are dynamic, then the partitioner has to wait for and depends on the parent(s) of those items.

Merge Input Attributes

When on, the partitioner merges the attributes of the work items in each partition and exports them to the partition itself.

Range

Range Type

Determines how the work item range is specified.

Custom

Custom range based on a ratio of upstream items to partition count and an offset in the left/right directions.

Fixed Count

Creates a fixed number of partitions no matter how many upstream work items there are. Upstream items are distributed as evenly as possible amongst the partitions. If the items don’t divide evenly, the first few partitions will have an extra work item.

Fixed Size

Creates partitions of a fixed size when possible. If the upstream items don’t divide evenly, only the last partition will have the wrong size. It will contain whatever items are left after dividing the upstream items into groups of the desired fixed size.

First/Last

Creates exactly two partitions. The first one contains the first work item from each of the input nodes, and the second partition contains the last work item from each of the input nodes. Other upstream items are not partitioned.

First/Middle/Last

Create exactly three partitions. Behaves the same as the First/Last range type, except the middle work items from each input node are also put into a partition.

Custom Range

These parameters configure the behavior of the partitioner when the Custom Range type is selected. The range is determined by two main properties: the ratio of upstream work items to partitions, and an offset in the left and right direction.

For example, with Upstream Range set to 2 and Partition Range set to 1, one partition will be created for every two upstream work items.

Upstream Range

Along with the Partition Range parameter, determines the ratio between upstream work items and partitions

Partition Range

Determines the number of partitions to create, along with the Upstream Range parameter.

Left Offset

The number of additional items proceeding the selected items that should also be included in the partitions.

Right Offset

The number of additional items that follow the selected items that should also be included in the partitions.

Fixed Count

Range Count

The number of partitions that will be created.

Fixed Size

Range Size

The number of upstream items that will be added to each partition.

Advanced

These are advanced parameters that provide finer control over the behavior of the partitioner.

Auto Remove Stale Dependencies

When on, the partitioner removes old dependencies when recooking the node if the partitioning scheme changes as a result of the cook.

Force Re-Evaluation on Cook

When on, forces the partitioner to re-evaluate the partitioning scheme even if all of the work items are already cooked and no new work items have been added.

Dirtying Mode

Determines when a partition is dirtied and the effects on child items when that occurs. This is particularity useful for working around some of the limitations of using dynamic partitioning.

Standard

A given partition is dirtied when any of the work items in the partition are dirtied. In the case of dynamic partitioning, if any ancestor of a dynamic work item in a partition is dirtied, then all partitions are dirtied.

When a partition is dirtied, all of its children are deleted.

Non-destructive

The same dirtying behavior as Standard, except when a partition is dirtied, its children are dirtied instead of deleted.

Mapping Standard

A given partition is only dirtied if an item in the partition is dirtied or if the partition’s contents change as a result of a recook. When the partition is dirtied, any child work items are deleted.

Mapping Non-destructive

The same dirtying behavior as Mapping Standard, except when a partition is dirtied, its children are dirtied instead of deleted.

Split by Attribute

When on, the node splits input work items by the specified attribute before partitioning them. The partitioning logic is evaluated on the list of work items for each distinct attribute value. Work items with different attribute values are always put into different partitions.

Missing Attribute

Determines how the node handles work items that are missing the split attribute.

This parameter is only available when Split by Attribute is on.

Ignore Work Item

Work items that are missing the split attribute are not put into any of the partitions.

Partitioner Defines Behavior

The partitioner node determines what happens to work items that are missing the split attribute. Typically a partitioner node that exposes this option will rename this menu entry to describe the actual operation it performs.

Add Work Item to All Partitions

Work items that are missing the split attribute are put into all of the partitions.

Sort Contents By

Determines the order that work items are sorted in when accessing the partitions on this node. This also affects the sort order of output files on the partition.

None

No sorting is applied. The work items in the partition are handled in no particular order.

Work Item Index

Work items in the partition are sorted based on their index.

Input Node Order

Work items in the partition are sorted based on the order of input nodes wired into this node. If two work items are from the same input, they are then sorted by index.

Attribute

Work items in the partition are sorted based on the attribute specified in the Sort Attribute field parameter.

Sort Direction

Determines whether the work items in this node’s partitions are sorted in ascending or descending order.

Sort Attribute

Specifies the name of the attribute to sort by.

This parameter is only available when Sort Contents By is set to Attribute.

Partition When

Determines when the partitioning step is performed on the input work items.

This parameter is only available when Use Dynamic Partitioning is on.

Input Items Are Generated

Inputs are partitioned once all of them have been generated.

Input Items Are Cooked

Inputs are partitioned once all of them are cooked. This is required when the partitioning scheme is based on the results of the work items' execution.

This makes this partitioner behave like a Wait for All node except that it may create multiple partitions.

Partition Target

Specifies the target TOP node for the partition. The partition scheme is applied to the work items in the target TOP node instead of this node’s input work items. The target TOP node must be a processor in the same graph above this node, and there cannot be any other mappers or partitioners between this node and the target.

This parameter is only available when Use Dynamic Partitioning is on.

Examples

example_top_partitionbyrange Example for Partition by Range TOP node

This example demonstrates the multiple partition options provided by the partition by range node.

See also

TOP nodes