Creating and moving checkpoints.

A scroll checkpoint shows up in two places at once:

• On the canvas as a colored horizontal line across the page, with a label on the right edge and a drag handle on the left. Visible only when you have a scroll animation selected.
• In the timelinebelow the canvas as a vertical tick on the X axis. Tick marks are labeled with the checkpoint’s name.

When no scroll animation is selected, the canvas overlay stays hidden so you can see your page without clutter.

Three ways to create a new checkpoint:

• Automatically with a new scroll animation. Clicking + Scroll in the sidebar creates a scroll animation along with two new auto-generated checkpoints (start and end). The animation references them.
• From the right panel.Inside any scroll animation, the checkpoint dropdown lets you create a new checkpoint inline. Type a name, click “Create”, and Glopzi places it just below the current viewport.
• By double-clicking the canvas overlay. Hover the page, find the Y position you want, double click. A new checkpoint appears at that exact pixel.

Two ways:

• Drag the handle on the canvas. The colored circle on the left edge of the marker line. Grab it, drag up or down, release. The page scrolls with you so you can land on a precise position.
• Edit the position values in the right panel. Open the checkpoint’s settings (from the timeline tick or from the animation’s checkpoint chip). Adjust the anchor element, the position on that element (top, center, bottom), or the offset.

When you move a checkpoint, every animation that references it updates at once. This is the point of the shared model: one source of truth for “the hero ends here” instead of the same value duplicated across multiple animations.

Double-click the checkpoint’s label in any of these places:

• The label on the canvas overlay (right edge of the line).
• The tick label on the timeline.
• The checkpoint chip in the animation’s right panel.

An inline input appears. Type the new name, press Enter to commit, Escape to cancel. The change shows up everywhere immediately.

To remove a checkpoint:

1. Right-click the checkpoint label on the canvas or the timeline tick.
2. Choose Delete.
3. If the checkpoint is in use, Glopzi tells you which animations reference it and asks for confirmation before deleting.

Animations that lose their start or end checkpoint continue to exist but stop animating until you assign a new one. They’re flagged in the sidebar with a warning indicator so you know to fix them.

• Anchored vs absolute markers covers what determines where a checkpoint “is” on the page.
• Coordinating multiple elements shows the killer use case for shared markers.
• Scroll-based animations explains how animations attach to checkpoints.