a9-phone-card-carousel

name	A9-phone-card-carousel
description	motion-graphic scene archetype — multiple phone-shaped cards conveyor-panning across the canvas at constant velocity. canonical UTURN / TikTok-feed look. partial cards at canvas edges imply infinite content. composes conveyor-pan as the sole motion + sticker-chip-pop overlays per card.

A9 — phone-card carousel

Composes

• conveyor-pan (the signature mechanic)
• sticker-chip-pop per card (tier-2, fires as each card enters the visible window)
• bg-swap on entry

Layout

canvas: 1080x1920 (or pack-specified)

outer_bg:
  color: pack.background (often black for SP-E)
  fills_canvas: true

card_strip:
  laid_out: horizontal flex
  card_width: 720
  card_height: 1280
  card_gap: 80
  card_radius: 32
  card_tilt_random: random_uniform(-8, 8, seed=card_index)   # for SP-E

cards_visible_at_once: 2.3                                     # partial cards at edges

Choreography

phase_1_conveyor:
  start_frame: 0
  effect: conveyor-pan
  velocity_px_per_sec: 360
  easing: linear

phase_2_per_card_stickers:
  trigger: card.entered_visible_window
  effect: sticker-chip-pop
  delay_after_entry_frames: 8

phase_3_no_hold:
  description: conveyor doesn't hold — it continuously moves through the scene

Style pack compatibility

supported: [SP-E]
preferred_in: [SP-E]
incompatible: [SP-A, SP-B, SP-C, SP-D, SP-F, SP-G]

This is an SP-E-specific archetype. The continuous-conveyor mechanic doesn't fit other packs' transition vocabularies.

Pack-specific overrides

SP-E (chaos-card)

• Card bg: each card uses a different saturated swatch.
• Card tilt: ±5-8° per card.
• Music beat anchor optional (conveyor is continuous, doesn't beat-lock).
• Card content: brand wordmark top-left + headline + product image.

Duration

duration_seconds: [4.0, 12.0]
default: 6.0      # ~3-4 cards visible during the scene

Driven by card count × visible window. Computed as (card_w + gap) × cards.length / velocity_px_per_sec.

Quality Checks

• Velocity is constant (linear, no spring).
• Partial cards visible at both canvas edges throughout.
• Card-tilt is randomized but seeded (deterministic across renders).
• Strip total width ≥ scene duration × velocity (so the strip doesn't run out).
• Sticker chips on each card fire AFTER the card enters the visible window, not before.

Failure Modes

• Conveyor pauses or stutters. Easing isn't linear. Force linear translateX.
• Strip runs out — white gap at canvas edge. Increase card count or duplicate the strip.
• Stickers pop on offscreen cards. Compute card visibility window correctly; only pop when card's bbox enters canvas bounds.
• Cards all tilt the same direction. Seeded random isn't varying enough; use full ±8° range.