Plasma `<mv-plasma>`

Fonctionnement

Fond WebGL de plasma magnétisé : quelques pôles magnétiques lents errent dans le cadre et leurs lignes de champ brillent en fins filaments, des arcs qui quittent un pôle pour se poser sur un autre, ondulés par une légère turbulence itérée. Des perles de courant voyagent le long des arcs, qui passent par trois couleurs d’un bout à l’autre. Le pointeur porte un petit aimant vers lequel se courbent les filaments proches. Dessiné sur le fond du thème : de l’encre sur du papier en thème clair, des lignes lumineuses en thème sombre.

Catégorie	Arrière-plans
Type	Élément WebGL (`<mv-plasma>`)
Statut	stable
Installe aussi	shader
Keywords	safe-rewrite, webgl, shader, plasma, field-lines, magnetic, filaments, turbulence, interactive, hero

When to use

A science, energy, AI or developer product wants a living hero backdrop that reads as precise rather than psychedelic
A launch or event page should answer the pointer with a visible but calm effect, in light and dark themes alike
A dark section needs glowing linework in the brand colors that leaves most of the frame quiet for a headline

Avoid when

Soft, flowing brand color fills the frame with no lines at all → use Mesh Gradient instead
Long body copy sits on top; the filaments cross behind it and hurt readability beyond short headlines

Installation

node scripts/add.mjs plasma --out ./src/marvelous

Agent IA avec le serveur MCP de Marvelous UI : install_components({ slugs: ["plasma"], target_dir: "<absolute path>/src/marvelous", framework: "react" }).

Fichiers copiés (dépendances comprises) : tokens/tokens.css, core/base.css, core/canvas.js, core/dom.js, core/element.js, core/i18n.js, core/motion.js, core/observe.js, core/webgl.js, components/shader/shader.js, components/shader/shader.css, components/plasma/plasma.js.

Utilisation

Balisage de référence : partez de celui-ci et personnalisez-le avec les attributs, data-* et les variables CSS :

<mv-plasma data-fill></mv-plasma>
<div style="position:relative;display:grid;place-items:center;height:100%;min-height:320px;padding:2rem 1rem;box-sizing:border-box;text-align:center;pointer-events:none">
  <div>
    <p style="margin:0;font:700 clamp(1.6rem,4vw,2.6rem)/1.1 var(--mv-font-sans);letter-spacing:-.03em;color:var(--mv-fg);text-shadow:0 0 28px var(--mv-bg),0 0 10px var(--mv-bg)">Held by the field</p>
    <p style="margin:.6rem auto 0;max-width:26rem;color:var(--mv-fg);text-shadow:0 0 16px var(--mv-bg),0 0 6px var(--mv-bg)">Move your pointer over the arcs: they bend toward it and spark.</p>
  </div>
</div>

API

Attributes

Name	Type	Default	Description
`colors`	CSS colors (3)	`var(--mv-accent), color-mix(in oklch, var(--mv-accent) 30%, var(--mv-fg-muted)), a hue 75 degrees before the accent`	Colors along each arc: at the positive poles, midway, at the negative poles. Tokens accepted, read again on theme change. The default third color follows --mv-accent-h and gets lighter in a dark theme.
`scale`	number	`1`	Size of the field (0.25 to 4): larger means fewer poles, longer arcs and a broader ripple.
`turbulence`	number	`1`	Strength of the ripple on the filaments, 0 to 3 (0 = clean field lines).
`intensity`	number	`1`	Filament and glow brightness, 0 to 3.
`density`	number	`1`	Number of filaments per pole (0.3 to 3, 1 = twelve).
`speed`	number	`1`	Time multiplier.
`paused`	boolean		Freezes the field on the current frame.
`interactive`	boolean		Follows the pointer only over the element (otherwise across the whole window).
`dpr`	number	`1.5`	Max pixel density (capped at 2).
`data-fill`	boolean		Fills the positioned parent (absolute, inset 0).

Events

Name	Description
`mv-error`	Inherited from `<mv-shader>`: the GLSL failed to compile. The element gets data-error and shows its fallback.

Content structure

Name	Description
`children`	Content placed inside the element sits above the canvas.

Accessibility

Decorative: the canvas is aria-hidden and never takes pointer events; content placed inside stays in the normal reading order. The loop stops off screen and in hidden tabs, and no WebGL context is created until the element comes near the viewport. Reduced motion (OS or <html data-motion="reduce">) and paused keep one still frame, with no pointer response. Forced colors and print hide the canvas; without WebGL2 a static sketch in the theme tokens is shown. The frame stays mostly the page background, but filaments can cross behind text: keep a headline short or give it a halo or panel in the background color.