Use for job.* when an approved output root exists. A submission saves a versioned source snapshot first; the child Blender process may write only inside its job directory. The foreground may continue editing, but the job remains bound to the submitted snapshot.
Route by kind: EXPORT and RENDER_STILL also use blender-render-compositing; BAKE_POINT_CACHES also uses blender-simulation. Use RENDER_ANIMATION_FRAMES for a persistent PNG or multilayer EXR sequence. Use COMPOSE_VIDEO only after its source FrameSequenceReceipt has complete frame hashes; it produces a separate H.264 receipt without rerendering Blender.
Query status until a terminal receipt and keep the job ID, snapshot hash, manifest hash, and artifact receipt together. Cancellation terminates only the child task. job.recover may mark a lost task interrupted but never restarts it. Resume only after an explicit job.resume; verified frames remain untouched while missing or hash-invalid frames are replaced. A background receipt does not approve external upload, publishing, payment, or Video Factory orchestration.
When to Use
Use when rendering, exporting, or cache baking would block the foreground, or when the task requires checkpoint recovery and per-frame validation. Operations that are fast and must be observed immediately should continue to use the corresponding foreground skill.
Prerequisites
- Submitted
sceneRevision + snapshotId, an approved output root directory, and non-overwrite constraints. - Clarify the task type, frame range, format, timeout, and disk budget, and confirm that the subprocess can read the dependency assets.
Workflow
Step 1. Select the job type based on the artifact and save an immutable snapshot.
Step 2. Submit the job and record the job ID, snapshot hash, manifest hash, and output directory.
Step 3. Poll until a terminal state; after an interruption, perform a recovery check first, and continue only with an explicit job.resume .
Step 4. Replace only missing frames or frames with hash errors, and finally generate a terminal-state receipt and artifact manifest.
Validation and Delivery Evidence
Verify the terminal state, exit code, snapshot hash, frame interval, per-frame hashes, file sizes, and media probe results. Video compositing must also prove that the input sequence is complete and that duration, frame rate, and dimensions conform to the agreement.
Rules and Capability Boundaries (Inapplicable Scenarios)
Background success does not mean the image quality has been accepted, nor does it authorize upload, publishing, or paid services. Jobs must not write outside the approved directory, and tasks in an unknown state must not be automatically restarted.
Gotchas (Common Issues and Recovery)
- Subprocess disappeared: mark as
interrupted, and retain logs and verified frames. - Single frame corrupted: locate it by hash and redo only that frame.
- Insufficient disk space or path out of bounds: stop immediately and report the actual path and space requirements.