Plan and Scene Authoring

Plan and scene authoring

The Plan defines the production. The Scene Prompt Editor makes its prompts comfortable to edit. Both represent the same saved data.

Recommended editing path

1. Give Plan a unique run_name.
2. Set shared defaults such as dimensions, duration, steps, transition, and audio policy.
3. Add one scene card per intended shot.
4. Edit the active scene in Scene Prompt Editor.
5. Use each card's Advanced section only for a deliberate override.
6. Run Preflight before loading H3.

Plan Studio and Rich Scene Prompt Editor are optional experimental interfaces. They do not change sampling quality or the generation graph.

Minimal Plan shape

{
  "defaults": {
    "duration_seconds": 10,
    "steps": 20
  },
  "shots": [
    {
      "id": "opening",
      "prompt": "A complete MiniMax H3 scene prompt.",
      "seed": "4201"
    },
    {
      "id": "continuation",
      "prompt": "The next complete scene prompt.",
      "seed": "4202"
    }
  ]
}

Scene cards write this structure for you. Raw JSON remains available when copying, reviewing, or generating a Plan programmatically.

Timing

H3 uses 24 fps and valid raw lengths on the 17k+5 grid. Requested seconds are rounded upward to the next valid frame count.

For continued scenes:

delivered frames = raw scene frames - repeated incoming context

The first scene loses no frames unless it continues an Existing Video Context. Use the timing preview in Plan or Preflight rather than estimating final length from requested seconds alone.

Prompt structure

Each scene should contain a complete instruction. A reliable Ref2VA layout is:

subject_definitions:
Define people, objects, and reference roles.

summary:
One clear sentence describing the scene.

retention_analysis:
State what must remain stable and what may change.

detailed_description:
Describe action, blocking, camera, lighting, timing, and transitions.

overall_soundscape:
Describe dialogue, ambience, effects, and synchronization.

non_diegetic_music:
Describe music, or write N/A.

Tagged references such as @hero stay readable while authoring and compile to native H3 labels only for scenes that activate them.

Seeds, revisions, and retries

• Store uint64 seeds as strings when editing JSON to avoid browser-number rounding.
• Prompt history is branching: a retry can create a new revision without erasing the accepted or earlier wording.
• Review Gate retry uses the active Plan/editor prompt. Its internal textarea is hidden by default in version 0.5.
• Reroll changes the active scene's seed and preserves the accepted predecessor.

Bounded work

scene_range accepts one scene (3) or one continuous inclusive range (3:8). It does not accept disjoint generation ranges because every continued scene depends on its predecessor.

Next: Plan reference, References and source media, or Review, resume, and recovery.