Paper Cinder Transition

A page does not fade into the next one, it is eaten by a line of fire. Reach for fire-paper-loader when the burn is a ring on a loading screen that must survive a blocked main thread; reach for this when the burn is the change between two scenes you own. For text that is written in by a mask rather than burned, use masked-reveal; for a scroll-scrubbed sequence with no burn, scroll-scrubbed-visual-sequence.

The mechanism

One full-screen pass decides, per pixel, whether it belongs to the frozen old frame (ahead of the line), to the burning zone (the line), or to the live new scene (behind it), from a single signed distance to a noisy front. Everything else is staging. Remove any of the three layers and it stops reading as fire: no frozen frame and the old page keeps moving under the flame, no live scene and the reveal is a still, no pixel-true distance and the edge is a soft blotch.