Labs Karma Render 2.0 TOP node

Renders images using Karma through TOPs with file versioning, wedging, and scheduling support.

This node provides a TOPs-based interface for rendering images with Karma. It wraps a Karma LOP render setup and integrates it into a procedural, scalable PDG workflow.

The Labs Karma Render TOP focuses on:

Consistent file and directory construction
Versioned image output
Frame range and wedge evaluation
PDG scheduling and batching
Loading and merging rendered results

It is intended for batch rendering, automation, and large-scale iteration workflows where renders must be managed, repeated, or parameterized efficiently.

This node does **not** replace Karma’s native render controls. Instead, it orchestrates when and how Karma renders are executed within PDG.

Parameters ¶

File Method

Controls how the output image path is generated.

Constructed: Builds the path automatically from the base folder, name, frame, version, and wedge.

Explicit: Uses the path specified directly in Image File.

Time Dependent Render

Marks the render as time-dependent, ensuring PDG evaluates frames correctly for animated renders.

Base Name

Base name used when constructing output image filenames.

File Type

Image file format written by Karma (for example: exr, png, jpeg).

Image File

Explicit output image path when File Method is set to Explicit.

Open Directory

Opens the directory containing the rendered images.

Base Folder

Root folder used when constructing output paths.

Open Directory

Opens the resolved Base Folder in the system file browser.

Open Sequence

Opens the rendered image sequence in the file browser.

Enable Version

Enables automatic versioning of rendered images.

Version

Version number appended to the output path when versioning is enabled.

Down Version

Decreases the version number.

Up Version

Increases the version number.

Caching ¶

Karma ¶

LOP Path

Path to the Karma LOP node that performs the actual rendering.

Cache Mode

Controls how PDG interacts with existing render outputs.

Automatic: Lets PDG decide whether to read or write.

Read Files: Loads existing renders without re-rendering.

Write Files: Forces rendering and writes new outputs.

Sequence ¶

Evaluate As

Controls how frames are evaluated.

Single Frame: Renders a single frame.

Frame Range: Renders a continuous range.

Specific Frames: Renders only selected frames.

Frame Range

Start, end, and increment values for frame evaluation.

F Menu

Quick presets for common frame ranges and increment patterns (including substeps).

Override Frame

Enables overriding the evaluated frame number.

Override Frame

The frame number to use when override is enabled.

List of Frames

Explicit list of frames to render when using Specific Frames.

Wedging ¶

Enable Wedging

Enables parameter wedging for render variation.

Evaluate As

All Wedges: Evaluates every wedge from 0 to Wedge Count - 1.

Single Wedge: Evaluates only the wedge specified in **Single Wedge**.

Custom Range: Evaluates wedges in the **Wedge Range**.

Specific Wedges: Evaluates only the wedge indices listed in **List of Wedges**.

Single Wedge

Index of the wedge to evaluate when rendering a single wedge.

Wedge Range

Start and end wedge indices.

List of Wedges

Explicit list of wedge indices to render.

Wedge Count

Total number of wedges generated.

Number of Attributes ¶

Attribute # ¶

Attribute Name

Name of the attribute being wedged.

Wedge Type

Method used to generate wedge values.

Min Value

Value range used for numeric wedge types.

Max Value

Value range used for numeric wedge types.

Seed

Random seed for stochastic wedge generation.

Batch Size

Number of values grouped per batch for batched wedges.

Period Size

Period length for periodic wedge sequences.

List of Values

Explicit values used for list-based wedging.

Geometry Path

Optional geometry path used for attribute-based wedges.

Default Value

Fallback value when an attribute cannot be evaluated.

Load ¶

Merge Frames

Enables merging multiple rendered frames into a single PDG result.

Merge Frames

Selects which frames are merged.

Frame Range

Start and end frame range to merge when Frames to Merge is set to Custom Range.

Substeps

Number of substeps per frame to include when merging frame ranges.

List of Frames

Explicit list of frames to merge when Frames to Merge is set to Specific Frames.

Merge Wedges

Enables merging wedge outputs.

Merge Wedges

Selects which wedges are merged.

Wedge Range

Start and end wedge range to merge when Wedges to Merge is set to Custom Range.

List of Wedges

Explicit list of wedge indices to merge when Wedges to Merge is set to Specific Wedges.

Scheduling ¶

Scheduler ¶

Scheduler Override

Overrides the TOP scheduler used to cook this node.

Override Priority

Enables overriding the work item priority.

Node Priority

Priority expression assigned to generated work items.

Local ¶

Cook Batch When

Controls when a batch of work items is cooked.

All Inputs are Ready: Waits until all upstream work items are complete.

All Frames are Ready: Waits until all frames for the current batch are available before cooking.

First Frame is Ready: Starts cooking as soon as the first frame becomes available.

Frames per Batch

Number of frames processed per work item batch.

Advanced ¶

Path Construction ¶

Frame

Evaluated frame number used for path construction.

Frame String

String representation of the frame number.

Version String

String representation of the version number.

Wedge String

String representation of the wedge index.

Cache Folder

Directory where rendered images are written.

Cache Name

Base filename used for output images.

Output File

Final resolved output image path.

Descriptive Label

Custom label shown on PDG work items, useful for identifying renders in large graphs.

See also

TOP nodes

Attribute Array

Creates and modifies array attributes on work items.
Attribute Classify

Creates a new attribute to classify work items by their unique attribute values
Attribute Copy

Copies attributes from work items in one branch onto work items in another branch.
Attribute Create

Creates or sets an attribute on all incoming work items.
Attribute Delete

Removes attributes from work items.
Attribute Dictionary

Modifies dictionary attributes by adding key/value pairs, removing keys, or merging existing dictionaries
Attribute Promote

Copies attributes and fields between work items, global attributes, and output files
Attribute Randomize

Create randomly-generated integer and float attributes on work items.
Attribute Reduce

Reduces array attribute values to a single value.
Attribute Rename

Renames attributes on work items.
Attribute String Edit

Edits string attribute values.
Attribute from File

Parses attribute values from a file into work items.
Attribute from Parameters

Creates a dictionary attribute filled with parameters from a target node
Attribute from String

Parses attribute values from a string, such as a file name.
Block Begin Feedback

Starts a feedback loop. TOP nodes within the block execute serially, optionally looping for each incoming work item.
Block End Feedback

Ends a feedback loop. TOP nodes within the block execute serially, optionally looping for each incoming work item.
CSV Input

Copies data from a CSV file into work item attributes.
CSV Output

Writes work item attributes to a CSV file.
Deadline Scheduler

The PDG scheduler for Thinkbox’s Deadline software.
Download File

Downloads the contents from one or more URLs into files.
Environment Edit

Edits the variables set in the environment work item command lines execute in.
Error

Issues warnings or errors when a condition is met.
FFmpeg Encode Video

Encodes a sequence of still images as a video file.
FFmpeg Extract Images

Extracts a sequence of still images from a video file.
File Compress

Compress files into an archive.
File Copy

Copies a file from one location to another, either at runtime or whenever the node generates.
File Decompress

Decompresses archive files specified by incoming work items into individual files.
File Pattern

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

Creates a range of work items based on files that match a certain pattern.
File Remove

Deletes a file at a specified path.
File Rename

Renames or moves a file.
Filter by Attribute

Filters upstream work items by their attribute names or values
Filter by Expression

Conditionally filters upstream work items.
Filter by Range

Filter upstream work items that fall within a specified frame or attribute range.
Filter by State

Filters upstream work items by their state
Generic Generator

Generates work items with no attributes that run a command line.
Geometry Import

Loads points or primitives from a SOP or geometry file into work item attributes or a temporary file.
HDA Processor

Creates work items that cook a digital asset
HQueue Scheduler

Schedules work items using HQueue.
Houdini Block Begin

Starts a Houdini service block
ImageMagick

Provides easy access to ImageMagick functionality such as mass image convert, resize, and image mosaics.
In Process Scheduler

Controls the scheduling of in-process work items.
Invoke

Invokes a compiled block on input geometry
JSON Input

Extracts data from JSON files and creates attributes
JSON Output

Performs various operations that produce JSON output
Labs Archive Project

Utility TOP to Collect and Archive current HIP file dependencies
Labs Concatenate Text

Merges one or more text files into a single file.
Labs Cut Geometry to Partitions

Cuts up incoming geometry
Labs Data Diff

Diffs a variety of geometry, text and image files.
Labs Extract Image Metadata

Extracts image metadata, such as the resolution, bit depth, color model, etc.
Labs File Cache

Caches (writes out once and then reads from) geometry (possibly animated) to disk.
Labs File Cache Filter

Partition work items used for file caching
Labs File Cache Partitioner

Partitions and generates work items based on range and wedge values for file cache.
Labs Filter by Value

Filters one or multiple work items by specific attribute values.
Labs Generate from Imageplanes

Generates work items based on image planes found in an image
Labs Karma Render

Renders images using Karma through TOPs with file versioning, wedging, and scheduling support.
Labs ML CV ROP Synthetic Data

The base template for synthetic dataset pipelines.
Labs Wedge

Creates work items with varying attribute values.
Local Scheduler

Schedules work items on the local machine.
ML Preprocess OIDN

Processes training and validation datasets for OIDN model training.
ML Regression Kernel

Trains a neural network for regression.
ML Train OIDN

Trains an OIDN model using preprocessed training and validation datasets.
ML Train Regression

Trains a neural network for regression.
ML Train Style Transfer

Trains a neural network for doing style transfer between image pairs
Make Directory
Maya Block Begin

Starts a Maya service block
Merge

Merge all upstream work items
Node Pattern

Creates work items based on matched nodes.
Nuke Block Begin

Starts a Nuke service block
Null

Does nothing
OP Notify

Notify an OP node that some TOP work has completed
OpenImageIO

Provides easy access to the OpenImageIO’s command line tool, also known as oiiotool, to perform operations on images such as color space conversion, color mapping, resizing, text overlay, and box overlay.
Output

Subnet output
Partition by Attribute

Partitions work items based on their attributes
Partition by Bounds

Partitions source items spatially using the bounding items.
Partition by Combination

Partitions work items into pairs, triples, etc
Partition by Comparison

Partitions work items using existing comparisons
Partition by Expression

Partitions work items based on an expression
Partition by Frame

Partitions work items based on their frame
Partition by Index

Partitions work items based on their index
Partition by Iteration

Partitions work items based on their feedback loop iteration.
Partition by Node

Partitions work items based on their node
Partition by Range

Partition work items based on range values
Partition by Tile

Partitions work items spatially using axis-aligned bounding boxes.
Perforce

Execute Perforce commands through PDG
Preflight

Copies a list of files into the scheduler’s working directory
Python Block Begin

Starts a Python service block
Python Partitioner

Partitions work items using a Python script
Python Processor

Generates work items using a Python script.
Python Scheduler

A Python-based programmable Scheduler for PDG.
Python Script

Creates work items that run a Python script.
Python Virtual Environment

Creates a Python virtual environment using TOPs
ROP Alembic Output

Creates work items that cook an embedded Alembic ROP node
ROP Composite Output

Creates work items that cook an embedded Composite ROP node
ROP FBX Output

Creates work items that cook an embedded FBX ROP node
ROP Fetch

Creates work items that cook a ROP node or network.
ROP Flipbook Render

Creates work items that cook an embedded Flipbook ROP node
ROP GLTF Output

Creates work items that cook an embedded GLTF ROP node
ROP Geometry Output

Creates work items that cook an embedded Geometry ROP node
ROP Image Output

Creates work items that cook an embedded Image ROP node
ROP Karma Render

Creates work items that cook an embedded Karma ROP node.
ROP Mantra Render

Creates work items that cook an embedded Mantra ROP node
ROP OpenGL Render

Creates work items that cook an embedded OpenGL ROP node
ROP USD Output

Creates work items that cook an embedded USD ROP node
Range Extend

Extend the frame range of upstream work items and adds new work items as necessary
Range Generate

Generates work items for the specified range.
Remote Graph

Connected to a remotely executing TOP graph and displays the nodes from that graph
Render IFD

Creates work items that render an IFD file with Mantra
SQL Input
SQL Output
Send Email

Sends an email.
Service Block End

Ends a service block.
Service Block Send

Sends code to a service block to execute.
Service Create

Creates a PDG service.
Service Delete

Deletes a PDG service.
Service Reset

Resets a PDG service.
Service Start

Starts a PDG service.
Service Stop

Stops a PDG service.
ShotGrid Create

Creates ShotGrid entities
ShotGrid Delete

Deletes entities from ShotGrid
ShotGrid Download

Downloads ShotGrid attachments
ShotGrid Find

Finds ShotGrid entities
ShotGrid Server Begin

Starts a persistent ShotGrid command server
Shotgun Update

Updates shotgun entities
Shotgun Upload

Uploads files to shotgun
Sort

Sorts work items by a list of attributes
Split

Splits upstream items in two
Split by Count

Splits upstream items into two using a fixed count
Subnetwork

Container for TOP nodes
Switch

Switch which between network branches
TOP Fetch

Cooks another TOP network.
TOP Fetch Input

Input to a TOP fetch-ed network
Text Output

Writes text to a new file or appends to an existing file.
Tractor Scheduler

Schedules work items using Pixar’s Tractor.
URL Request

Creates work items that request data from a URL.
USD Add Assets to Gallery

Adds USD assets to the Asset Catalog.
USD Analyze

Fetches metadata, dependencies, and external references for a LOP Node or file.
USD Import Data

Creates work items from prims found in a USD stage.
USD Import Files

Creates work items from file references found in a USD stage.
USD Modify Paths

Modify asset path attribute values.
USD Render Files

Creates work items that render a USD file.
USD Render Scene

Creates work items that render a USD file or LOP network
Wait for All

Waits for all upstream work items to complete.
Wedge

Creates work items with varying attribute values.
Work Item Expand

Expands file lists or partitions into multiple work items
Work Item Import

Import work items from a .json file or another TOP node.
Xml Input

Extracts data from XML into Work Item attributes