Scroll participation, sections & snaps

01What has to scroll first

Sections and participation are measured against an artboard's scroll range. The artboard's own Scroll section (next) is how far and how smoothly that range moves. Give the content a taller (or wider) area than the frame — the panel tells you when it doesn't.

02The Scroll tab

Open Scroll on the timeline. Empty, it says Scroll sections live on an artboard — draw one (A) and put layers inside it.

Once there is a board:

No sections yet: “+ Section” marks a stretch of this artboard’s scroll where the layers you pick stop moving and hold in place.

A list row that overlaps another on the same axis shows ⇄ Name. That badge is the scroll junction — not a bug. See When two sections overlap.

⧉ copies the section at the same range with the same held layers — then drag the new band. Ctrl+Z undoes delete.

03The artboard's Scroll section

Select the artboard. Scroll in Properties is the frame itself, not a child.

The wheel scrolls the artboard in Play. In the editor, use the rail.

04Scroll Participation on a layer

+ Add › Scroll Participation (Parallax, pin, hold) is how a child of a scrolling artboard opts in. The same row is under Add › Motion on the context menu. It only does something when the layer's direct parent is a scrolling artboard.

Factor is 1 / 1 on every new layer: the layer scrolls with the content, same speed as everything else. Changing it is the parallax.

X and Y are independent. A horizontal gallery can parallax on X and stay at 1 on Y.

Hold is not Factor 0

Factor 0 is sticky for the whole scroll. Changing it while the playhead is mid-scroll jumps the layer, because the offset is scroll × factor on every frame.

A hold is a window. The layer scrolls in, freezes for that stretch, then continues — no jump at the edges. + Hold in a section creates a section on the parent artboard, ticks this layer into it, and opens the Scroll tab so you can size the band. If the layer is already held, the row lists every section (Name · 20–45%) and each chip jumps to that band.

A layer can be held by more than one section. Removing Scroll Participation with × puts Factor back to 1 / 1 and takes the layer out of every hold.

05Sections

A section is a named stretch of that artboard's scroll. Click a row — or a band — to edit it.

Detail

Drag the band or type the range — they are the same numbers.

Hold in place

Tick a child. It scrolls in, stands still across the band, then continues — no jump at the edges. Click the layer name to select it on the canvas.

A layer can be held by more than one section. The tick on this section does not steal it from another.

• Between two non-overlapping holds the layer scrolls normally. The row shows +N (Also held by “Outro”).
• If two holds on the same axis overlap, the windows merge into one longer freeze. The row shows ⧉N and the tooltip says so.

Each held layer also outputs Held in place 0 → 1 across this section. Bind a property to that (or drive a sequence from it) to animate while the layer stands still.

06Drives

A section's product is a number: 0 at the start of the band, 1 at the end, then it stays at 1. Drives is who is listening.

The hint: Pick "Scroll section → {name}" as the source anywhere a value is asked for — a sequence driver, a page timeline, or any bind.

Drive a sequence

If the scene has sequences, a picker — drive a sequence — lists them. Pick one:

• The source becomes Scroll section → this name.
• ⇥ turns on (this is the only setup that actually plays — without it, only the already-active sequence's driver runs, and the scrub looks dead).
• A chip ∿ Intro appears with ⇥ and ×.

⇥ on: Takes over the playhead inside this section — click to stop. Off: Only the ACTIVE sequence's driver runs.

Scrolling through the band plays that sequence from start to end. The rail playhead is live: drag it and the artboard actually scrolls, so you see hold and release without Play.

× on the chip stops the driver. The same bind also shows under Whole scene → Scene as a Drive row — one sentence, two doors. Sequence drivers is the Sentences side; ∿ Drive sequence from scroll on the artboard is the whole scroll (0 → 1 of the frame), not one section.

Drive a property

Binds that already read this section appear as chips (∿ Card · Opacity). Add one from the property: right-click the badge → ∿ Add binding… → Scroll › Scroll section → this name. Streams & variables.

Empty: Nothing follows this section yet.

07When two sections overlap

Two bands on the same axis that share a range show ⇄ Name on the list. That overlap is a junction.

If each section drives a different sequence, the engine does not cut hard at the edge. Across the shared range the two playheads crossfade — weight and both sample times come from scroll, so rolling back unwinds the same blend. This is not a cable on the Sequences graph and not Auto on end. Those fire on a clock or a rule. This one is tied to the wheel.

Do not overlap two activating drivers unless you want that mix. The inspector warns when two ⇥ drivers compete.

A transition you wire in the blend graph (Crossfade / Sync scrub / Parallel / Page curl) is a different tool: a named blend a sentence can call. Use the graph when a click or On Sequence End should change films. Use a rail overlap when scrolling should ease from Intro into Spin.

08Pick the tool

09Snaps

A snap is not a section. It is a catch on the same rail, drawn on its own row underneath the bands: where the wheel should settle. Click ◇ — the detail column switches from the section to the snap.

Three handles on the rail:

Stop the wheel anywhere inside the zone and the scroll eases to the diamond.

This is still not the artboard Snap row (a pixel grid on the wheel).

10Fine adjustment

The rail starts showing the whole 0–100%. For a tight overlap, zoom it the way you zoom the timeline:

A hint under the rail repeats this while you work.

11Shortcut recap