Houdini 20.0 Nodes Render nodes

USD Stitch Clips render node

Merges multiple value clips representing individual frames.

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Since 18.0



The Geometry Clip Sequence LOP should be used in preference to this node in most situations.

This render node generates a value clip definition given a list of USD files, each representing a single frame of data that should be incorporated into the value clip.

This produces two output files:

  • The topology file contains the union of all primitives and properties and metadata that exist in any of the source files.

  • The template file contains a scene graph with a single leaf primitive that references the topology file, and sets up the value clip arcs to each of the individual source files (that will, during playback of this file, each contribute it’s opinions to the primitives referenced in from the topology file).

    Normally you would sublayer the template file into a stage to add the value clip to an existing primitive. However the template file may also be referenced into a stage.

The source files must each contain data set at a time sample that corresponds to the time when that clip file is active. If the clip files only contain default values, the values read from the clip files will not animate.


  • This ROP is very similar to the usdstitchclips script that comes with USD, except it can stitch many sequences of layers together in a single operation.

  • See the Value Clip LOP for authoring value clip compositions from clip files that you know match the topology of an existing branch of your scene graph hierarchy.

  • See the USD documentation for more information about Value Clips.



Click to generate the clip files.


Controls the frame number values that are used to determine the sequence of USD files that should be stitched together. No data is generated from nodes in the hip file when executing this ROP, so the frame numbers are only used to generate per-frame file names that are stitched together.

Set Time Codes per Second

Controls the setting of the Time Codes per Second and Frames per Second values in the generated template file.

Specific Value

Use the value specified in the Time codes per second parameter.

From First Clip

Use the time codes per second metadata value from the first clip file.


Do not set the time codes per second metadata on the template file.

Time Codes per Second

If Set time codes per second is Specific value, this parameter’s value is written to the template file’s time codes per second metadata.

Stitch Files

The number of stitching operations this node will perform. Each stitching operation will generate a separate pair of topology and template files.


Enables or disables a single stitch clip operation.

Input File

The file path to to a clip file to stitch. This file path should include the frame number, for example dance_$F.vclip.

Template File

File path to write the template file to.

Clip Primitive Path

Scene graph path within the individual clip files that is the root of the hierarchy that should be stitched together by the value clip. This same path is also used as the path to the leaf primitive in the template file that will hold the reference to the topology file, and the list of clips.

Clip Set Name

A single USD primitive may have multiple value clips, each of which can contribute data to some portion of the scene graph contained by the primitive with the value clip specifications. To do this, each set of value clip information must be given a name, which controls the sub-key under the clips key where the information for that clip set is stored.

Generate Separate Manifest Layer

In addition to generating the value clip layer, and the associated topology layer, this option enables the creation of a manifest layer. The manifest layer describes which attributes are meant to be animated by the value clip files. With this option disabled, the topology layer is used as the manifest layer. This works in many cases, reduces the number of layer files to deal with, and avoids the additional time required to create the manifest layer. However the separate manifest layer will make the composition of the value clip more efficient and addresses some problems that can arise such as with the handling of non-indexed primvars.

Report Output Files

Prints the paths of files that are written to disk.

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