VCR Manifest Author

Write valid, deterministic VCR manifests and validate them before full renders.

Workflow

1. Define or update version, environment, and layers in the target .vcr file.
2. Run validation:
   • vcr check <scene>.vcr
3. Run quick visual verification:
   • vcr render-frame <scene>.vcr --frame 0 -o renders/<scene>_f0.png
4. Build final output:
   • vcr build <scene>.vcr -o renders/<scene>.mov
5. If parameters are used, enumerate and test overrides:
   • vcr params <scene>.vcr --json
   • vcr build <scene>.vcr --set key=value -o renders/<scene>_variant.mov

Authoring Rules

• Always include at least one layer.
• Use unique non-empty id values for all layers.
• Keep image paths relative to the manifest directory.
• Treat t as frame number, not seconds.
• Prefer typed params for reusable manifests.
• Re-run vcr check after every meaningful edit.

Success Criteria

• vcr check exits with code 0.
• A frame preview is generated successfully.
• Final render artifact exists at the expected output path.

Failure Handling

• Unknown field/variant: fix key spelling or enum value and re-run vcr check.
• Expression failure: replace unsupported functions with supported expression functions and retry.
• Missing dependency: run vcr doctor and resolve FFmpeg/toolchain issues.
• Shader/post effects not visible: ensure GPU backend (--backend gpu or auto) is used.