Page transition

Arch Portal Reveal

by Vanguardia · motionprompts.dev

A sticky stage where an arch-shaped opening grows from a small doorway to the entire frame as you scroll, revealing the scene behind it. The scene never scales: it keeps its own viewport-sized box and is anchored to the same bottom-centre point as the opening, so it sits perfectly still while the aperture grows around it — scaling the container instead would balloon the type, lose the photograph's crop and read as a zoom rather than as walking through a door. The arch is `border-radius`, not `clip-path` (a real curve, no facets, two numbers to animate instead of a polygon whose vertex count must stay constant), and the radius is pulled down on a `pow(1-p, 1.9)` curve so the shape is unmistakably an arch during the first third, which is the part the reader watches. One ScrollTrigger writing directly on every update, no scrub; Lenis supplies the smoothing. Dressed as a glasshouse: Playfair Display + Kumbh Sans, moss green and chalk.

Type: Web motion
Framework: GSAP
Trigger: scroll

Save with a free account Customize for your product

Live demo ↗

Motion spec · measured by motionprompts.dev

Engine: gsap
Complexity: 1/5
Pinned: no
Reduced motion: handled
Libraries: gsap, ScrollTrigger, lenis

sticky stage over a 260svh track where an arch-shaped opening grows from 26vw/34svh to 100vw/100svh by writing --w/--h/--r on every ScrollTrigger update; the radius follows pow(1-p,1.9) so the arch reads as an arch through the first third; the revealed scene keeps a viewport-sized box anchored to the same bottom-centre point and never scales; no tween, no scrub, smoothing from Lenis only

The build prompt

From motionprompts.dev

Creator's promptVanguardia · motionprompts.dev13,242 charsCustomize

# Arch Portal Reveal — a doorway that grows until it is the whole frame

## Goal

Build a pinned stage where an **arch-shaped opening grows from a doorway to th…

The build prompt

More like this

A one-line prompt for an inference startup launch

UX Decision Explainer Animation

Motion Design Showreel Reaction Video

SaaS launch video for a product Opus picks

Product video for Distilbook

Squad.so SaaS Launch Video

Fresh recipes, every week.