Houdini 18.0 Nodes TOP nodes

File Pattern TOP node

Creates work items based on files that match a certain pattern.

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This node generates a work item for each file (and/or directory) name that matches a pattern in a directory (and optionally all sub-directories).

The pattern field specifies the path to start searching in as well as the pattern to match. For example, $PDG_DIR/geo/*.bgeo finds all files ending in .bgeo, looking in the geo directory inside the project working directory.


The pattern is always expanded on the machine where the network cooks, not on a remote host on the render farm. The expanded file names should still be under the working directory in the shared network filesystem. The node will automatically convert local matched file paths to paths that are relative to the working directory.

See the pattern parameter for an explanation of the pattern syntax.

This node has two modes for generating work items:

Whenever this node is asked to generate items (when it cooks, or when you ask nodes to pre-generate static items), the node checks if the pattern matches different files from the last cook, and also if the modification times have changed on any files. If so, it updates and marks dirty the changed items. So if the directory contents change, normally only the changed items need to recook.

TOP Attributes

When Split Files into Separate Items is on, the node sets the following attributes on each work item.



The directory containing the file associated with the work item, without the file name or extension.



The extension of the file associated with the work item. Not set if File Types is set to Directories Only or when the globbed path is a directory.



The name of file, including the extension if Include Extension in Filename is enabled. Not set if File Types is set to Directories Only or when the globbed path is a directory.


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.

File Types

Whether to match Files Only, Directories Only, or All (both files and directories).


Match file paths against this pattern. Note that the pattern specifies where to look for files, for example $PDG_DIR/geo/*.bego. The pattern allows wildcards such as ? (match any character), * (match any string of characters), and [abc] (match any one of the characters inside the square brackets). For example, *.png matches any file that ends with .png.


Also look for matching file names in sub-directories of the path specified in the pattern parameter.

Output File Tag

When this is on and Split Files into Separate Items is off, assign this file tag to the output file paths. If this is off, the node guesses appropriate file tags based on filename extensions.

Split Files into Separate Items

When this is on (the default), the node creates separate work items for each matched name, with the file name data stored in attributes. When this is off, the node creates one work item, with the matching file paths set as the item’s output results. Turning this off can be useful if the node you're wiring this node into operates on results data.

No Match Behavior

The behavior of the node if no matches were found.

No Match Behavior

The behavior of the node if no matches were found.

Attribute Name

The name of the attribute to create on each work item which will indicate whether or not the file was found.

Include Extension in Filename

Include file extensions in the filename attribute.


example_top_filepattern Example for File Pattern TOP node

This example demonstrates how to use File Pattern to load files using a match expression.

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