# Morph Explainer Video > Turn a fact, a body question, or a script into a finished vertical morph-explainer short: the deadpan anatomical/body-horror format that reads as one unbroken morph, the subject deforming continuously against a flat cyan backdrop while a flat narrator reads 165 words a minute over a wall-to-wall bed. Built end to end on Unsora: keyframe chain via create_image, morph segments via create_video (seedance-2.0 image + lastImage), one-take narration via create_voiceover (ElevenLabs v3), bed via create_music, then ffmpeg stitch and a -14 dB master. Use when the user wants a video in this style, says "make a Zack D. Films style video", "body horror explainer", "cursed science short", "morph video", "what if you did X to a human body", "turn this fact into a short", or hands over a script or a weird body fact and wants the finished MP4. Also use for a single morph segment's prompt pair, or to write only the script to the house templates. Default to this for any deadpan anatomical explainer built on continuous morphs. - Skill: `sadekxd/morph-explainer-video` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add sadekxd/morph-explainer-video` - Raw SKILL.md: https://api.skillmd.com/api/skills/sadekxd/morph-explainer-video/raw - Safety review: pending (external: skill-scanner PASS, skillspector PASS) - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: AI & ML - Author: sadekxD (https://skillmd.com/u/sadekxd) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/sadekxd/morph-explainer-video --- # Morph Explainer Video A fact in, a finished vertical short out — in one fixed house style, on Unsora. Or just the script, or one segment's prompts, if that's all they want. **The idea in one line:** pick the script format → write to its beat template → **voice it first** → cut the picture to the voice → chain keyframes so the film reads as one unbroken morph → score it → master to −14 dB. **The pipeline in one line:** ``` elicit (format, subject, length) → write script to template → [GATE 1: script] → create_voiceover (ONE take) → ffprobe → derive keyframe times & segment durations → keyframe + segment plan → [GATE 2: shot plan + credits] → create_image K0..Kn (chain: each Ki is referenceImage for Ki+1) → create_video per segment (image=Ki, lastImage=Ki+1) → ffmpeg concat → create_music (mureka-7.5) → mix: bed + VO + 2 stings → −14 dB RMS → final.mp4 ``` If they want only the script, run Part 1 and stop at Gate 1. If they want one segment's prompts, run Part 1 + Phase 4 for that segment and stop. **Two required reads before writing a single prompt:** 1. `references/house-style.md` — the twelve slots, filled once and **locked**. This style does not vary. Read it before any prompt. 2. `references/pipeline.md` — the exact Unsora calls, the keyframe chain, the ffmpeg mix, the master target. And one of `references/formats/hypothetical.md` or `references/formats/true-story.md` before writing a word of script. --- # PART 0 — THE FRONT DOOR Three parameters. Infer what you can; ask only what's missing. On a client with tappable inputs, use them. 1. **Format** — which script architecture: - **`hypothetical`** — "If you did [absurd thing] to a body, what happens?" Ends on a deadpan punchline. ~117 words / ~43s. - **`true-story`** — "This actually happened to a person." Ends on "now they plan to…" ~94 words / ~33s. A "what if" or "can you" phrasing answers this — don't re-ask. A real named person or event answers it the other way. 2. **Subject** — the body fact or question. If they gave a script, read it and classify against the templates. If they gave a bare topic, you write the script; that's Phase 1. 3. **Length** — default to the format's native length. Only ask if they want a non-standard runtime, and warn: these templates are tuned to their word counts, and stretching them dilutes the format. Orientation is **not** a parameter. It is always 9:16. Neither is the look — there is one house style and it is locked. Never generate (which spends the user's Unsora credits) before Gate 2. --- # PART 1 — THE LAWS ## The style DNA never varies Unlike a multi-style producer, this skill has **one look**, defined in `references/house-style.md` and locked across every film. What varies is the **script architecture** — that's the swappable profile here. Slots 1–11 of the house style are constants; only slot 12 (the hook rule) forks by format. ## Cut freely; morph only inside a shot **This section was wrong until it was measured.** An earlier version claimed "one hard cut in 77 seconds" and treated cutting as a rare concession. The opposite is true, and building to the old rule produces glitchy welded joins. Measured on reference R1 (37.70s): **6 shots, mean 6.3s, median 5.25s, shortest 2.8s, longest 11.1s** — hard cuts at 4.90 / 16.03 / 21.17 / 29.53 / 32.30s, plus 22 softer boundaries. **Budget 5–8s per shot. Cuts are the default grammar.** Two independently generated clips will not join invisibly. Do not try. Give each shot its own start frame and cut cleanly; continuity comes from consistent character and setting references, not from welding. Morphing is what can happen *inside* one clip when a shot happens to run long — it is not the structure of the film. Two levels: - **Inside a segment — never cut.** One Seedance clip morphs smoothly from its start frame to its end frame, both pinned (`image` + `lastImage`). A cut appearing *within* a clip is a real failure (the model inserted a shot change) and the negative prompt kills it. - **Between segments — cut.** This is the normal case, roughly every 5–8s. Two independently generated clips will not join into an invisible take; forcing it reads as a glitch. A **match cut** (segment *i*'s end keyframe reused as segment *i+1*'s start) is available when a beat genuinely continues the same action, but it is one option among several, not the default — R1 uses honest scene cuts for most of its six boundaries. Never paper over a scene change with a crossfade. If the beat changes, cut. **The chain, mechanically.** Segment *i* is generated with `image: K_i` and `lastImage: K_i+1`; segment *i+1* is generated with `image: K_i+1`. For a match cut those two are the identical file. The morph prompt still says "single continuous take, no cuts" — that governs the *inside* of the one clip. ## Voice first, picture second The narration is the spine. The VO is generated **as one unbroken take** before any picture exists, then the picture is cut to it. This inverts the usual picture-first order, and it's correct here for three measured reasons: the reference films have **zero silence** (never below −21 dB), the read is one continuous deadpan with no per-shot gaps, and the segment boundaries are loose (8–12s) rather than tight beats. Timing the voice to the picture would fight all three. Practical upside: one `create_voiceover` call for a whole 117-word script is ~650 characters = **6 credits**, versus 6 credits × 8 segments if you chop it up. ## Nothing is ever static Zero pixels in the reference films hold still. Measured on R1: mean temporal standard deviation across the whole frame is **63.2** (of 255), per-shot range 40.7–63.6, frame-to-frame mean absolute difference median **23.0**. (An earlier version of this file claimed 15.9; that number had no source.) This is a dense, fast edit — subjects cross frame, camera pushes and drifts, action fills the shot. A shot where only the camera moves over a static subject is below standard. Which leads to: ## No text in generated frames — but the finished film IS captioned Two rules, previously conflated into one wrong rule: 1. **No text in any keyframe prompt.** Not a title, caption, label, or lower third. If a prompt would put a word on screen, delete it. 2. **Captions go on in post.** R1 carries a white caption layer throughout, synced to narration. An earlier version of this file claimed the reference films had no text at all — that was an observation error. The only exception to rule 1 is a word that exists as a **physical object in the world** (the "SALINE" printed on a syringe barrel, the "NEW PLAN" stamped on a clipboard) — that's a prop, not a title. ## 165 words per minute Measured: 161.5 and 169.5 WPM; 2.69 and 2.82 words/second. Write to **2.75 wps** and the runtime falls out of the word count. A beat's word budget is fixed by the format template — respect it, because the templates are the format. ## Spend nothing before the gate Two gates. Script approved at Gate 1 (free). Shot plan + credit estimate approved at Gate 2 (before the first generate call). Unsora has **no cost-preflight parameter** — unlike some connectors, you cannot price a job without submitting it. So quote an estimate, check `get_credits`, and get an explicit yes. ## The two-prompt structure Every segment is two artifacts: - **Keyframe prompts** (image model) — one per *state*, not per segment. An n-segment film has **n+1 keyframes**. Ordered: Subject → State → Setting → Style → Camera → Lighting → Constraints. Each keyframe carries the house medium sentence and the AI-default negative. - **Morph prompt** (video model) — names both frames by role ("the shot opens on the start frame and resolves to the end frame"), never re-describes their design, states the deformation in the house motion verbs, and closes with the audio line. ## The frame-zero problem, inverted Most producers fight the hero frame being the *end* state. Here both ends are pinned — `image` and `lastImage` are both supplied — so the model's job is purely to interpolate. The failure mode flips: the model **arrives early and holds**, producing a morph that finishes at 4s and then sits dead for 7s while inventing motion. The fix is in the prompt: state the deformation as *continuous across the full duration* ("the change is gradual and unbroken across all N seconds; it is never complete before the final frame"). See the failure table. --- # PART 2 — THE PRODUCTION PIPELINE Read `references/pipeline.md` for exact Unsora parameters before Phase 5. ## Phase 1 — Script Read the format profile, then write to its beat table. Every beat has a word budget; hit it within ±2 words. If the user supplied a script, classify it against the two templates and say plainly where it deviates — a script with no punchline isn't `hypothetical`, it's a `true-story` that needs a "now they plan to" ending. If the `anti-slop` skill is available, run the draft through it. This is public-facing copy and the format dies instantly on AI narration voice — no "in a world where", no "the results may surprise you", no hype adjectives. **Gate 1: show the script and wait for a yes.** Show it as the beat table with word counts and estimated seconds. Free to change here, expensive later. ## Phase 2 — Voice it, then measure One `create_voiceover` call, whole script, one take. Voice, stability, and the `<#x#>` pause-tag placement are in `references/pipeline.md` §2. Then `ffprobe` its real duration. **That number is the film's runtime.** Everything downstream is derived from it, not from the plan. ## Phase 3 — Derive the keyframe plan Split the VO's real duration into segments. Seedance 2.0 accepts only these lengths — **4, 5, 6, 8, 10, 12, 15s** — with **15s the hard ceiling** (not 20; Unsora's schema allows 20 across all its models, but Seedance rejects anything over 15 and anything off the fixed set). Work in **8–12s** segments, floor 6. **Two constraints fight, and the legal-duration one wins.** A boundary wants to land on a beat end *and* make a segment whose length is on the allowed set. You cannot always have both exactly, so resolve in this order: (1) mark every beat-end time as a candidate boundary; (2) choose the set of candidates whose gaps each **round to an allowed value within ±1.5s**; (3) if a gap still can't be made legal (e.g. a 13.7s stretch that would round up to 15 and overshoot), **move the boundary earlier onto the previous beat end** rather than forcing 15 — never let a segment exceed its real content, and never pick a duration off the set. Only after the durations are legal do you lock the split. Place boundaries on **beat boundaries**, never mid-sentence. Then: - `n` segments → `n+1` keyframes, `K0 … Kn` - `K0` is the film's first frame; it must already show the premise. The hook sentence says "like this" and points at something that is *already on screen at 0:00*. There is no establishing beat. - `Kn` is the last frame — the punchline state (`hypothetical`) or the future-facing state (`true-story`). - Each interior `Ki` is a designed *state* on a beat boundary: the thing the deformation has become by then. A 43s film → 4 segments (10/10/10/12) → 5 keyframes. A 33s film → 3 segments (12/12/10) → 4 keyframes. Every length is on Seedance's allowed set. When a raw gap lands between two legal values, round to the nearer and absorb the ±1–2s slack across the other segments so the total still matches the VO. When the concat is built, a segment generated at a legal length can be **trimmed** to its exact beat window in ffmpeg — so prefer generating the nearest legal length *at or above* the raw gap and trimming down, rather than generating short and leaving a gap. **At each boundary, decide the cut type** (this is a Gate-2 decision): - **Match cut** (default) — same subject continues deforming. The end keyframe of segment *i* IS the start keyframe of segment *i+1* (one shared image), so the join is nearly seamless. - **Scene cut** — the beat changes location (e.g. the field → the operating room). Segment *i+1* gets its own fresh `K` and the boundary is an honest cut. Keep these rare; the reference films use about one. ## Phase 4 — Write the prompts, then stop Write all `n+1` keyframe prompts and all `n` morph prompts. Show them in the per-segment format below. **Gate 2: the shot plan.** A table, then the numbers, then wait: | Seg | t_start → t_end | Sec | Start K | End K | Cut in | The deformation | VO beats | Below it: the keyframe list (one line each — `Ki` at `t`, one sentence of the state), total runtime, segment count, keyframe count, and — plainly — that generating spends Unsora credits, roughly `n+1` image jobs + `n` video jobs + 1 music job (the VO is already paid for), and takes roughly `n × a few minutes` of polling. Report the current balance from `get_credits`. Do not call a generation tool before an explicit go. **Per-segment output format:** 1. `### SEGMENT N — [TITLE]` + one line: the deformation and why it lands. 2. **Breakdown** — duration; VO beats covered; start state; end state; the deformation; camera; the accent color, if any; audio. 3. **Start keyframe prompt** — fenced block. (Skip if already written for the previous segment's end — each keyframe is written **once**.) 4. **End keyframe prompt** — fenced block. 5. **Morph prompt** — fenced block. ## Phase 4.5 — Calibrate against a real frame. MANDATORY. **Never generate a full keyframe set from an unvalidated prompt.** This phase exists because the style vocabulary is genuinely hard to hit and the failure is invisible from the prompt alone — it only shows up next to a reference frame. 1. Pick the single hardest keyframe in the plan (most character detail, most palette range) and generate **one** image from it. 2. Extract the nearest matching frame from a reference video: `ffmpeg -ss -i -frames:v 1 -q:v 2 ref.jpg` 3. **Look at both.** Compare on four axes, in this order: | Axis | Right | Wrong | |---|---|---| | Render medium | Game-engine uncanny | Photoreal, or Pixar-polished | | Grade | Warm browns vs desaturated teal | Neutral, teal lost | | Depth | Background falls off hard | Everything sharp | | Framing | Subject large, foreground crowds bottom | Centered portrait | 4. If any axis is off, fix the prompt and re-run **one** image. Iterate here, where it costs one image, not after twenty. 5. Only when the frame matches, carry the corrected style block into every keyframe prompt and proceed. **Do not skip this because the prompt "looks right".** In the calibration run that produced the current house style, iteration 1 read as perfectly reasonable and was wrong — it landed in the animated-feature ditch because it contained the words "high-end animated feature". One 2-credit image caught it. **If the generator accepts reference images, use them.** Passing the actual reference frame in as a reference beats describing it in words. Check the generator's image tool for a `referenceImages` parameter before falling back to text-only calibration. ## Phase 5 — Generate `references/pipeline.md` has the exact calls. In order: 1. **Keyframes, in chain order, `K0` first.** Each `Ki+1` passes `Ki`'s result URL in `referenceImages` — this is what keeps the subject from redrawing itself between states. Poll each with `wait_for_image` before generating the next; the chain is strictly sequential. 2. **Segments.** `create_video` with `image: Ki_url`, `lastImage: Ki+1_url`, `model: seedance-2.0`, `aspectRatio: "9:16"`, `duration: `, `generateAudio: false`. Segments are independent of each other and can be fired in parallel — they're pinned at both ends, so nothing drifts. (A scene-cut boundary just means segment *i+1* uses its own fresh `K`, not the shared one.) 3. **Music.** `create_music`, `mureka-7.5`, instrumental, no lyrics. Keep the manifest updated after every call so a failed segment regenerates without touching the rest. Never re-roll a completed segment "for consistency" — the keyframes already guarantee it, and a re-roll returns different. ## Phase 6 — Assemble and master `ffmpeg` concat the segments → `picture.mp4`. Verify its duration against the VO's. Then the mix: bed ducked under VO, VO at unity, 2 stings on the beats the format marks, **master to −14 dB RMS with peaks under 0.98**. Exact commands in `references/pipeline.md` §6. Verify the final duration against `picture.mp4` — a dropped segment yields a valid file that's simply the wrong length. Present with `present_files`. Offer, never perform, a social post. --- ## Failure table | Symptom | Cause | Fix | |---|---|---| | A **match-cut** boundary looks like a jump, not a continuation | The two keyframes aren't the same file — segment *i+1*'s `image` isn't the identical URL as segment *i*'s `lastImage` | Re-read the manifest; for a match cut both must be the same string. #1 silent failure. (If the boundary was *meant* to be a scene cut, this is fine — leave it) | | Morph finishes early, then the shot sits dead and invents motion | Both ends pinned, model raced to the end | State the change as continuous across the full duration and never complete before the final frame; if it persists, shorten the segment | | `duration` rejected or clamped | Passed a value off Seedance's set (e.g. 11, 13, 20) | Use only 4/5/6/8/10/12/15; 15 is the max. Re-split so every segment lands on an allowed value | | Looks like real live-action / stock medical footage | The AI-default betrayal for this style | Add the house medium sentence + the photoreal negative to **every** keyframe prompt | | A shot change appears *inside* one segment | Video model inserted a cut within the clip | "Single continuous take, one shot, no cuts, no scene changes" in every morph prompt + the cut terms in the negative prompt | | A forced-seamless join looks like a glitch (ghosting, stutter) | Tried to weld a real scene change into one take | Make it an honest cut instead — the format allows between-segment cuts | | Subject redraws itself between keyframes | `referenceImages` chain not carried | Every `Ki+1` must pass `Ki`'s URL in `referenceImages`; regenerate only the drifted keyframe and everything after it | | Words appear on screen | Text leaked into a keyframe prompt | No titles, ever. Delete. Only physical props may carry printing | | Cyan drifts to blue/teal between segments | Backdrop hex not restated | The exact hex goes in every keyframe prompt, not just the first | | Film is shorter than the VO | A segment failed and got skipped | Check the manifest, regenerate the missing segment | | VO runs past the picture | Segment durations derived from the plan, not the real VO | Re-derive from `ffprobe` of the VO; the voice is the clock | | Narration sounds hyped / performed | Wrong `stability`, or the copy is over-written | `stability: 0.75`+, and cut the adjectives — the format is deadpan | | Mix is quiet next to real feed videos | No master stage | Normalize to −14 dB RMS; the reference films both measure exactly that | | Music drowns the narration | No ducking | Sidechain the bed under the VO | ## Checklist — per segment, before generating - The deformation is a real *change of state*, not a camera move on a static thing. - The house medium sentence **and** the photoreal negative are in both keyframe prompts. - Keyframe prompts ordered Subject → State → Setting → Style → Camera → Lighting → Constraints. - The exact backdrop hex is restated in every keyframe prompt. - No text in frame anywhere, unless it's printing on a physical prop. - Morph prompt: only house motion verbs; "single continuous take, no cuts"; the change is continuous across the full duration; closes with the audio line. - `aspectRatio: "9:16"` on every image and video call. - `duration` is one of 4/5/6/8/10/12/15, identical in the plan and the call. - At a **match-cut** boundary, segment *i+1*'s `image` is byte-identical to segment *i*'s `lastImage`. At a **scene-cut** boundary, segment *i+1* uses its own fresh keyframe (and that's intentional). ## Checklist — before delivering - Script hit its template's word budgets; VO is one take; no intro, no outro, no CTA. - Picture duration matches VO duration within ~0.3s. - No cut appears *inside* any single clip — verify with `ffmpeg select='gt(scene,0.3)'`. Detections at segment *boundaries* are expected for scene cuts and fine; a detection *mid-segment* is a failure. - Exactly 2 stings, on the beats the format profile marks. - Bed is continuous, never silent; ducked under VO. - Final master ≈ −14 dB RMS, peak < 0.98. - No burned-in text; full-bleed 9:16. --- ## Reference files - `references/house-style.md` — the twelve slots, locked. The medium sentence, the AI-default negative, the exact palette, the motion verbs, the prompt templates. Read before any prompt. - `references/pipeline.md` — exact Unsora calls (`create_image`, `create_video` with the `image`/`lastImage` chain, `create_voiceover`, `create_music`, the `wait_for_*` pollers), the ffmpeg concat and mix, the −14 dB master, the manifest schema, resume-after-failure. - `references/formats/hypothetical.md` — the 8-beat "what if you did this to a body" template. ~117 words / ~43s. - `references/formats/true-story.md` — the 5-beat "this happened to a person" template. ~94 words / ~33s. - `references/formats/format-framework.md` — how to build a third format profile without breaking the house style.