# Cuts, seams and motion

> Make every scene change read as one move, avoid the two cuts that fail in every register, and keep motion inside a shot calm and causal.

Module: Launch films · Level: intermediate · 8 min · https://school.agents.org.in/media/film/cuts-and-seams

Here is one scene change done three ways, laid out the way a reviewer checks it: frames a tenth of a second apart, either side of the cut.

*[Interactive demo: A contact sheet around the cut. Look for frames where nothing changes, and for a frame neither shot contains.]*

The dead cut shows identical frames on both sides of the cut. The crossfade shows a grey frame that belongs to neither shot. The cut on motion just looks like one card throwing to the next. That last one is the craft of this lesson.

## Films cut, and that is fine

A hard cut (An instant jump from one shot to the next, with no fade or transition between them. Most launch films use them) is an instant jump from one shot to the next. 26 of Skale's 29 films and 14 of the 18 acclaimed films hard-cut. Banning cuts forces every film into a continuous morph, which only five of the 47 chose.

How often a film cuts belongs to its register. Pick one below and feel the difference.

*[Interactive demo: Thirty seconds of film at each register's measured cut rate. Untick “Varied” for an even rhythm.]*

An even rhythm is a metronome. The films that feel alive vary it, and many end a run on an **accelerating ladder**: figma-launch cuts nine times on holds shrinking .8, .5, .4, .3, .2, .15, .12, .1 s, then lands on a hold.

## The two cuts that always fail

  **Step: The dead cut.** A settled frame, then a scene that waits. The outgoing shot is not moving on the cut frame, and the incoming one does nothing for more than ~0.3-0.4 s. The film stalls.

  **Step: The crossfade dip.** Both scenes fade at once, so at the midpoint whatever is underneath shows through: the page's white, a different background. Fade through a ground both scenes share, or cut.

A crossfade (The flash you get when two scenes fade at the same time: at the midpoint, whatever is underneath (often white) shows through) is not banned. 11 of 29 Skale films dissolve or dip (0.45 s median). Adaline dips to its paper colour; Extend dips through its brand colour. Those pass because the ground is shared.

## Where the eye accepts a cut

A good cut lands where the eye is already going. The measured places:

- **On the click.** Linear Agent clears the input on Enter, cuts 0.7 s later to the prompt already posted.
- **On a constant ground.** Keep one world or layout and cut freely; Raycast cuts 9 times in 28 s.
- **On the element being read.** A 2-3× scale jump of the same thing, anchored so it lands where it really sits.
- **Into motion.** Cut mid-drift on a moving camera, or onto things already travelling.
- **Inside a fill.** The Gemini app hides all four of its cuts in full-frame glyph fills.
- **To a still frame that acts within a beat** (0.3-0.4 s).

## Seams: what carries the eye

A seam (Any change from one scene to the next, whether a cut, a fill or a morph. A good seam reads as one continuous move) is any scene change, cut or not. It reads as one move when the outgoing element is still travelling on the last frame and the incoming one carries on: same axis, same direction, matched speed.

**One current per film.** Pick one dominant direction (leftward is a common default) and spend the others on purpose: up for a conclusion, a pull back for an arrival.

| Seam | How it works | Timing |
|---|---|---|
| Fill the frame | a pressed button or shape grows until its colour is the next ground | 0.33 s median |
| Zoom-through (A seam where the outgoing scene pushes in and blurs, the scene swaps, and the new one arrives from slightly smaller, as if the camera flew through) | out 1 → 1.2 with blur, hard swap, in from 0.75 | out 0.2 s, in 0.5 s |
| Zoom into type | letters grow 4-6× until they fill the frame | 0.33 s median |
| Shared element | one object carries across: a pill becomes a progress bar becomes a chart bar | ~2 s chains |

The thing that crosses is the carrier (The thing that crosses a scene change and carries the eye with it: a button filling the frame, a dot, a line that becomes a chart). Use **2-3 seam types** per film, one of them for 60-70 % of the changes.

*(Write the seams down before animating: one row per seam, typed cut, match-cut or morph, with what exits and what enters.)*

## Motion inside a shot

Inside a shot, things arrive on a fast exponential settle and leave on the mirror curve. The speed of a settle is its time constant (How fast an exponential settle comes to rest. A smaller tau settles faster; about 0.1 to 0.15 seconds for an object in a film): about **0.1-0.15 s** for an object, slower for long travel (Raycast's big crane ~0.43 s, counters 0.6-0.8 s).

- **Nothing decorative moves on UI.** No float, pulse or breathe. A slow camera creep under a hold is fine.
- **Overshoot is a register,** not a default: only 4 of 29 Skale films and 3 of 18 acclaimed show visible bounce. Never spring a camera.
- **Blur is a choice.** Velocity blur peaks around 10 px on text, 18-20 px on full-frame surfaces. Plenty of films whip completely sharp.
- **Decisions are stamped, not tweened.** A typed letter, a selection hop, a page swap happens in one frame.
- **A cause launches its effect.** Click, squash, release, impact. That is what makes a film feel lively, not bounce.

**Cut and seam a launch film (paste into your agent):**

```text
Plan every scene change before animating. For each seam write one row:
type (cut / match-cut / morph), what exits and what enters, axis and
direction. Rules: no dead cuts (one side always moving, or the new shot
acts within 0.3-0.4 s); no crossfade between two opaque scenes unless
they share a ground; one dominant direction for ordinary seams; 2-3
seam types, one primary. Inside shots: exponential settles (tau
0.1-0.15 s for objects), nothing decorative moving on UI, no spring on
the camera.
```

**Check yourself:** Two dark scenes on a white page are crossfaded over 0.6 s. What does the viewer see at the midpoint?

- [ ] A smooth blend of the two scenes
- [x] A grey flash, because the white page shows through
- [ ] Nothing, crossfades are invisible
- [ ] The first scene frozen

*Why:* When both scenes fade at once, their summed opacity drops below 1 and the page underneath shows through: the crossfade dip. Fade through a ground both scenes share, or hard-cut.

## In the skill

- https://school.agents.org.in/skill/launch-video/launch-video-cuts.md
- https://school.agents.org.in/skill/launch-video/launch-video-seams.md
- https://school.agents.org.in/skill/launch-video/launch-video-motion.md