task_chunking

Task Chunking Job Bundle Samples

These samples demonstrate the Task Chunking extension for Open Job Description, which improves resource utilization by grouping multiple frames or tasks into chunks instead of processing them individually.

Why use task chunking?

Render jobs often spend significant time loading applications and scene files before rendering each frame. Chunking amortizes this overhead by processing multiple frames or tasks per chunk, reducing total job runtime.

Sample index

This table covers every immediate sample directory in task_chunking/.

Sample	What it demonstrates	Start here when
Basic contiguous chunks	CHUNK[INT] with rangeConstraint: CONTIGUOUS and start/end parsing	Your command accepts consecutive frame ranges
Basic non-contiguous chunks	CHUNK[INT] with arbitrary sparse frame sets	Your command accepts lists such as 1-3,5,7-20:2
Blender contiguous chunks	Applying contiguous task chunks to a frame render	Blender should load once for several consecutive frames
Blender non-contiguous chunks	Applying scheduler-selected non-contiguous chunks to a frame render	Blender can render arbitrary frame lists per task

The Blender variants add the TASK_CHUNKING extension and a ChunkSize parameter to the base Blender render sample. They change the frame task parameter from INT to CHUNK[INT] and set a target runtime so the scheduler can adjust chunk size.

Template structure

specificationVersion: 'jobtemplate-2023-09'
extensions:
  - TASK_CHUNKING

steps:
  - name: Render
    parameterSpace:
      taskParameterDefinitions:
        - name: Frame
          type: CHUNK[INT]
          range: "{{Param.Frames}}"
          chunks:
            defaultTaskCount: 10          # Default frames per chunk
            targetRuntimeSeconds: 600     # Optional target used to adjust chunk size
            rangeConstraint: CONTIGUOUS   # or NONCONTIGUOUS

Range constraints

Constraint	{{Task.Param.Frame}} expands to	Use when
CONTIGUOUS	"1-10", "11-20"	The application supports start/end frame arguments
NONCONTIGUOUS	"1-3,5,7-10"	The application supports arbitrary frame lists

References

• RFC 0001: Task Chunking
• Open Job Description specification