Transitions

At the end of this page every cutA cut is the change from one world to the next. of your film has a named handoffA handoff is the thing that carries the eye across a cut, such as a match cut, a shared axis or a colour flood.: the one thing that leaves beat A and starts beat B. Or the cut is a hard cut, chosen on purpose.

An agent asked to join two beats writes the same few seams: a crossfade, a whip pan, a slide-up and a scale-in. Choose each seam for a reason.

The prime rule

A seam must serve the relationship between the two beats, or the feeling across the seam. If it serves neither, the seam is a hard cut. A hard cut is the default, and in professional edits it is the great majority of seams. The rule hard-cut-default puts hard cuts at 50 to 95 percent of seams: the high end for a kinetic film, the low end for a calm one. “It looks smoother” is not a reason.

Choose a seam for each cut

bin/vawe check transitions films/<name>/page.html
bin/vawe check slideshow films/<name>/page.html

The vawe-transitions skillA skill is a SKILL.md file of instructions that an agent loads for one task, such as vawe-page for writing a page. gives an agent this procedure.

The twelve families

A family names what carries the viewer across the seam.

Three limits apply to the families:

• No family on two adjacent cuts.
• No family more than twice in a film. A deliberate cut is exempt from both limits.
• The strongest family, “camera through”, appears once in a film.

Time the seam

The ranges are in taste/rules/seam-timing.md. A seam is felt, not measured: round to the frame.

A whip that is not fast and blurred reads as a slow slide. A hard wipe edge reads as a slide deck, and a feathered edge reads as graded.

Speed

The seam is the verb and the timing is the adverb. A seam with no speed profile reads flat. Write a ramp with an EASE name from core/motion/presets.js.

Give the whole film one velocity personality. Calm films decelerate in, branded films use ramps, and hype is snappy.

Align the beats to the seam

The outgoing beat ends at the seam and the incoming beat starts at it. If both beats are on screen across the cut, a blend mixes two nearly identical stages and the copy turns into an unreadable double. A morph element is the exception: it spans the cut.

Do not let the frame go empty across a joint. Several frames of emptiness mean the outgoing beat left before the incoming one arrived. Overlap the beats by 0.2 to 0.4 s.

Put the next headline where the eye already is. Read the focal point of the frame before the cut, and put the incoming subject at or near that point.

The ten slideshow tells

bin/vawe check slideshow <page> scores the film out of 10 and prints each tell that fired, with its second and its fix. It is advice, never a failing exit.

The thresholds are repeat counts: 3 or more cuts, 5 or more elements, a 75 percent share. One crossfade for a time jump is a choice, not a tell.

Waive a check with a reason

Both checks advise. To keep a seam that a check names, declare a waiverA waiver is a declared break of a check rule, with a measured reason, in the page's <script id="authoring"> block. in the page. The reason names a second and a measured value. See Waivers.

<script type="application/json" id="authoring">{"allow": ["transitions"], "_why": {"transitions": "the cut at 7.8 s is a plain fade: 1.1 s of calm between two held frames"}}</script>

Troubleshooting

From the blogMotion graphics transitions: 12 types, 10 mistakes