vawe-transitions: one handoff per cut

Run this skill inside a vawe checkout: AGENTS.md, taste/ and bin/vawe live there. With no checkout, get one: git clone https://github.com/vawe-hq/vawe.git && cd vawe && npm install && bin/vawe-dev doctor.

A model asked for a transition writes the same few: a crossfade, a whip pan, a slide-up, a scale-in. This skill makes the choice on purpose. The grammar (the twelve families, when each fits, its cost, moves to copy) is in taste/craft/transitions.md "The twelve handoff families": read it first, it is not repeated here. Seam timing is rule seam-timing; the eye at a cut is in the same craft doc. This file is the procedure.

Run it for every cut of the Board's cut table, then write the result in its handoff (family: object) column and the ledger table.

Per cut

1. What changes, what carries over. One line: place, state, scale, time, a reveal or a payoff changes. Name the handoff object: the one thing that leaves A and starts B, with its screen position, scale, direction and speed on both sides. If nothing carries over, the family is deliberate cut and you write why (on a beat, for shock, a tonal flip).
2. Run guides/IDEATE.md for the cut. Write the cut's row in the brief's ## Ideas table: the meaning, 4 ideas with 4 different devices, a typicality number for each, the pick and why. The twelve families below are the device list for a cut: each idea names one family and the object, its anchor, direction and speed. The method owns the 4 ideas and the typicality; this file does not repeat it.
3. Write the pick in the handoff cell. The chosen idea's family and object go in the Board's handoff (family: object) column. A pick that fits any similar film is a default.
4. Check the ledger (the Board's second table, filled from the handoff column):
   • no family on two adjacent cuts;
   • no family more than twice per film (a deliberate cut is exempt: hard cuts are most seams, rule hard-cut-default);
   • the spectacle cut gets the strongest device of the film, and no other cut competes with it (quiet before it);
   • camera direction never reverses across a cut without a reason.
5. Defaults need a reason. Plain fade, crossfade, whip pan, slide-up reveal and scale-in each need because ... in the handoff cell (a dissolve for passing time between calm frames is a reason; "it looks smooth" is not).
6. Slideshow tells. Read "Banned (slideshow tells)" in taste/craft/transitions.md; none of the ten may describe your plan. bin/vawe check slideshow <page> scores the draft.
7. Surprise question. Which cut would a viewer predict? Replace it, or write why the plain one is right.
8. Execution notes, one line per cut in the motion pass:
   • z-order: the handoff object sits above both beats until the new one covers the frame; the old layer does not pop off first;
   • speed matched at the seam: read bin/vawe frame <page> --moment <s> --velocity on both sides, the exit must not decelerate into an entrance that starts from rest;
   • a flood reaches the farthest corner in about 0.35 s and has a reveal point, else it just cuts;
   • the transition is shorter than the beat it joins;
   • sound sits on the handoff frame: a J or L cut, or the effect on the frame the object lands.

Row format

| s2 to s3 | type-fill-transition | ... | ... | ... | ... | ... | ... | type-driven: the word "ship" becomes the ground |

A cut with nothing to carry: deliberate cut: lands on the downbeat, the tone flips.

Check

bin/vawe check transitions films/<name>/page.html [--mp4 out/<name>-draft.mp4] and the draft's advice name: a cut with no planned handoff, one family on adjacent cuts or more than twice, a plain fade with no reason, and a planned handoff that measures as a hard cut. Advice only. The slideshow check scores the ten banned tells. Waive in the page: code transitions, with a reason that names a second and a measure.