Fractal-noise dissolve from the top down, with a glowing edge on the front.
one renderer, three effects
Two <details> with different effects (dissolve and wipe) and a <dialog> with its backdrop, all sharing one canvas and one WebGL context. The effect is chosen per element.
Dissolve (default effect)
Wipe (another effect, same renderer)
A left-to-right wipe with a noisy edge. Different fragment shader, same canvas and context.