Houdini 17.5 Nodes TOP nodes

Invoke TOP node

Invokes a compiled block on input geometry

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This node can be used to run a SOP compiled block on input geometry. The geometry can either be from result data on an upstream work item, or the in-memory geometry representation produced by the Geometry Import TOP node.

When generating from partition, the invoke will expand the partition items into separate inputs to the compiled block.

TOP Attributes



The path that the work item where the work item will write its output geometry, if the Write Output parameter is enabled.



The number of points in the output geometry.


integer array

The indices of the upstream items that were used as inputs to the Invoke operation. sourceindex[0] is the first input to the compiled block, sourceindex[1] is the second input, and so on.


Work Item Generation

Whether this node generates static or dynamic work items. You should generally leave this set to "Automatic" unless you know the node’s work items can be computed statically, or that they need to be generated dynamically.


This node always creates dynamic work items: it waits until the upstream work items are known, and generates new work items from the upstream work items.


This node always creates static work items: it creates the number of work items it thinks it needs based on the parameters (and any upstream static items) before the network runs.


If the input is static (a static processor, or a partitioner with only static inputs, or a mapper), this node generates static work items, otherwise it generates dynamic work items.

Compiled Block

The path to the compiled block end node.

Evaluation Time

When this parameter is enabled it overrides the time used when evaluating the block. By default, the compiled block will be evaluated at the frame value specified on the work item, or at time=0 if no frame is set.

Input Geometry

The number of inputs passed to the compiled block. Must be at least one, and can only be more than one when generating from a partition.

Block Input Name

The name of the input as specified on the corresponding compiled block begin node.

Write Output

When this parameter is enabled, the results of the compiled block will be written to disk.

Output Path

The path to write the resulting geometry, if Write Output is turned on.


example_top_invoke Example for Invoke TOP node

This example demonstrates how to run compiled blocks using pdg data as input.

The following examples include this node.

example_top_invoke Example for Invoke TOP node

This example demonstrates how to run compiled blocks using pdg data as input.

See also

TOP nodes