Houdini 18.5 Nodes TOP nodes

Filter by Expression TOP node

Conditionally filters upstream work items.

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Since 17.5

This node evaluates an expression for each upstream work item to determine if the upstream item should be filtered out. You can also invert the filter so that matched work items are retained by setting the Operation parameter to Keep Matched Items.

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.

Operation

Determines whether this node should remove any work items that match the Filter Expression or keep the work items that match the filter

Filter Expression

Evaluates the specified expression for each upstream work item. When the result is 1/true, the upstream item is filtered out. Otherwise, the item is copied by this node.

Include Output Files

When on, output files from the upstream item are included on the copied work items.

Examples

FilterStringAttrib Example for Filter by Expression TOP node

This example demonstrates how to use the strcmp HScript function along with the Filter by Expression TOP node.

FilterWorkItems Example for Filter by Expression TOP node

This example demonstrates how to filter upstream workitems so that the remaining set can be further processed or debugged.

See also

TOP nodes