Scene authoring

Plan structure

The Plan node provides a visual editor and stores ordinary JSON underneath. Put shared instructions in prompt_prefix; each scene should describe what changes.

{
  "prompt_prefix": "Keep the same performer, wardrobe and visual language.",
  "defaults": {"duration_seconds": 15, "steps": 20},
  "shots": [
    {"id": "intro", "prompt": "Instrumental opening in the elevator.", "seed": 123},
    {"id": "street", "prompt": "Continue outside into the rain.", "seed": 456}
  ]
}

Prompts may be multiline strings or arrays of lines. Seconds are rounded up to H3's valid 17k+5 frame grid. Use length when exact raw frames matter.

The complete format guide documents every Plan and per-scene field, raw versus delivered length, prompt structure, seeds, and timing.

Chapter resolution

Click the chapter marker in Plan Studio to choose Inherit from Plan or Chapter resolution, with Width and Height in multiples of 32. Each chapter has one size; the next chapter inherits the Plan default, not the previous chapter's override. Wire Current Shot width/height to conditioning so its latent and reference preparation match the active chapter. The combined Current Tagged Ref2VA Scene node already handles this internally.

The existing scene lock also pins a chapter to its locked saved scenes' size. For example, lock Chapter 1's saved scenes, then change the Plan default or set Chapter 2's resolution. Chapter 1 stays at its saved size. A conflicting explicit size for Chapter 1 is rejected until its saved scenes are unlocked. Locking an ungenerated slot cannot pin a size. Locks do not bypass prompt/model identity, artifact-integrity, or native latent compatibility checks.

Different-sized chapters need an independent video boundary: set the new chapter's first scene's video context to zero for AV masking or latent Guide. Export each chapter separately with Chapter Delivery. Whole-run assembly cannot combine different sizes automatically. Saved media is never resized; recovery snapshots retain the resolved chapter size.

In Plan JSON the optional field is, for example:

{"id":"chapter_2","title":"Chapter 2","start_scene_id":"scene_08",
 "resolution":{"width":1344,"height":768},"text":""}

Omit resolution (or set it to null) to inherit. Chapter titles and notes remain editorial only and do not change generation identity.

Per-scene LoRA routes

Each scene has a Scene LoRA route selector: Base or LoRA A-D. Connect Current Shot state to MiniMax H3 Scene LoRA Scheduler, connect the normal base MODEL to base_model, and connect MODEL outputs from ordinary ComfyUI LoRA loaders to the A-D inputs. The scheduler only routes those prepared models; it never chooses a file or applies a LoRA.

One route can contain a stack of ordinary LoRA loaders. The same LoRA at two strengths can be represented by two branches. Inputs are lazy, so a connected branch is not evaluated until a scene selects it. Put patches shared by every scene after the scheduler. When using Drift-Control, send the scheduled MODEL through Chain Context's MODEL input/output before the sampler.

Scene Prompt Editor

Connect Plan to MiniMax H3 Scene Prompt Editor for a large synchronized textarea. It edits the selected scene's real shots[n].prompt; there is no second prompt copy.

Arrow buttons or Alt+Left/Right change scenes.
Typing @ offers the connected Picture/Video/Audio aliases. In Tagged mode, inserting an inactive alias activates it; scheduled references remain limited to the selected scene.
Typing # offers valid dedicated Semantic Picture Anchors (and legacy Tagged Picture compatibility anchors) only.
Typing < offers H3 subjects, dialogue tags, and available native reference labels, plus <scenetrans> and <|cutoff|> dialogue-flow markers. Typing [ filters 12 shot markers, multilingual dialogue markers, and canonical summary-intent combinations; for example, [re lists the supported reference-generation combinations. Typing (S offers stable speaker IDs.
Typing the start of an H3 section name at the beginning of a line completes subject_definitions:, integrated_multimodal_description:, and the other standard sections. Ctrl+Space (Cmd+Space on macOS) opens the full H3 completion catalog. Use arrows to select and Enter or Tab to insert.
@ Reference remains available for browsing connected media previews.
Dialogue wraps a selection in <d> tags.
Choose Auto schema, T2VA, I2VA, FL2VA, L2VA, or Ref2VA, then open Sections to inspect the exact required order, jump to a category, insert a missing category, or normalize the mode's keyframe-alignment line. Diagnostics cover section spelling/order, shot numbering and timestamps, Ref2VA task directives and definitions, dialogue/language/flow balance, and connected native references. FL2VA/L2VA expose duration and final-shot controls for their exact alignment sentence.
Live word/character counts stay in the footer. Both dedicated editors can switch between the ordinary prompt source and rich H3 token presentation; this changes presentation only, never Plan text.
#picture adds an untimed Qwen-only semantic Picture when the picture is supplied through Semantic Anchor Bundle. Add a time as #picture[2.50s] for a scene-local Qwen checkpoint; with the Bundle set to picture_storyboard, the time becomes an approximate prompt instruction. Neither form consumes a native H3 reference slot.
A− and A+ change persistent type size.
The node may sit inline before Loop Start or on an editor-only branch.

The reference tray discovers downstream Scheduled Ref2VA, core Ref2VA, and core Image to Video nodes without introducing an execution socket or graph cycle. Hovering a loader-backed reference previews its image, video, or audio; computed tensors remain usable even when no browser-playable source file can be found.

The schema inspector and completion catalog are shared by the focused Scene Prompt Editor and the optimizer-enabled Rich Scene Prompt Editor. They are backported from the standalone H3 Prompt IDE, while these nodes retain Motion Context Plan synchronization, revisions, @tags, semantic anchors, and optimizer integration.

Editor interactions

Click a Subject, speaker, dialogue, lyrics, caption or flow token to replace or remove it. Pasted tokens become interactive immediately. Connected media references keep their existing reference/syntax/time popup and previews. Ctrl/Cmd-click an ordinary [Shot N], language, task directive or retention marker to change it without replacing the surrounding sentence.

Inside retention_analysis:, completion offers visual or audio retention values according to the reference kind, including known @aliases and #picture anchors. Inside detailed_description:, typing [Shot N] At offers At 00:00.000, , selecting the seconds/milliseconds for immediate editing. Ctrl/Cmd+Space also offers the timestamp after a plain At in that section.

ComfyUI Settings → MiniMax H3 Context Loop → Prompt editor controls the default Rich/Plain presentation, automatic suggestions, optional trailing spaces, and the new marker replacement menus. Saved per-node presentation choices win. Trailing spaces are off by default to preserve existing typing behavior; semantic anchors never receive an inserted space before their time. Turning off automatic suggestions still allows Ctrl/Cmd+Space.

Ctrl/Cmd+S saves the workflow while the editor is focused. Ctrl/Cmd+Z remains scene-local. Token diagnostics flag malformed lyrics/caption pairs, incorrect special-token case, and legacy <cutoff>; they do not rewrite saved prompts or change generation. No task-aware Edit templates or new node sockets are introduced by this port.

Prompt revisions

The compact ‹ Active current / total › selector below the editor activates a prompt version in the Plan; it is not a read-only history browser. Each version is labeled Active draft, Active executed, Draft history, or Executed history. Typing updates one active draft rather than creating a revision per keystroke. When Current Shot executes, that exact prompt becomes immutable; typing from it creates a child draft. Activating an older version explicitly replaces the selected scene prompt in the Plan.

History is stored outside Plan JSON and loaded only for the selected scene:

output/h3_chains/<run_name>/prompt_history/<scene_id>/

The Plan retains only the active prompt, keeping workflow JSON readable and load time independent of old revisions.

Seeds and bounded runs

Set a scene seed explicitly when repeatability matters. If omitted, Plan derives a deterministic seed from base_seed and scene identity.

Loop Start's scene_range accepts one continuous selection:

Value	Result
blank	`start_clip` through the end
`3`	scene 3 only
`3:8`	scenes 3 through 8, inclusive

A range starting above scene 1 requires the preceding checkpoint. Disjoint selections are rejected because skipped scenes would break the motion chain.

Prompt Assistant status

The embedded Prompt Assistant is currently dormant so the editor retains its compact manual workflow. Use the comfyui-mcp sidebar Agent panel for Codex or Hermes assistance. The implementation, safety model, and future console-agent design are preserved in the Prompt Assistant study.