Houdini 20.0 Nodes TOP nodes

Merge TOP node

Merge all upstream work items

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Since 17.5

This node combines all upstream work items from all input nodes. For example, if one input node has 10 work items and the other has 15, this node will have 25 work items.


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.


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.

Merge Failed Work Items

When this toggle is enabled, the merge node will also included failed upstream work items. Note that if this option is only meaningful if the merge node is dynamic, and generates from cooked inputs.

Extra Inputs

Extra input nodes to the merge, which can be specified through node path parameters instead of via input connectors. Extra input nodes need to be in the same network as the merge node.

Extra Input

The node path to an an extra input.


Merge Example for Merge TOP node

This example demonstrates how to use the merge TOP to combine work item lists from multiple nodes.

See also

TOP nodes