ARCANE_FRAG

const ARCANE_FRAG: string

import { ARCANE_FRAG } from '@driftengine/core';

In depth

Pairs with PLUME_VERT, exactly as FIRE_FRAG does — the vertex stage only builds a world-fixed cross of quads, and which effect that cross becomes is entirely a fragment-stage decision. So this costs no new renderer and no new geometry path.

Where a flame is carved vertically — a taper toward the tip, a threshold rising with height, so it licks and breaks up — a spell is carved radially. Everything below works in polar coordinates about the quad centre: a bright thin core, a wide soft corona, and two noise bands turning in opposite directions.

The counter-rotation is the whole effect. One band turning alone reads as a sheet being spun, which is the same flatness BLADES describes for a billboarded fire; two bands shearing against each other have no single rotation to read, so the eye gets motion without direction. That is what separates a spell from a lamp on a dimmer.