@polygonjs/polygonjs/src/core/geometry/operation/Jitter.ts

node-based WebGL 3D engine https://polygonjs.com

import {Vector3} from 'three';
import {CoreGroup} from '../Group';
import {randFloat} from '../../math/_Module';
import { CorePoint } from '../entities/point/CorePoint';
import { CoreObjectType } from '../ObjectContent';

interface JitterOptions {
	amount: number;
	mult: Vector3;
	seed: number;
}

const _offset = new Vector3();
const _p = new Vector3();
const _points: CorePoint<CoreObjectType>[] = [];

export function jitterOffset(i: number, seed: number, mult: Vector3, amount: number, target: Vector3) {
	target.set(
		2 * (randFloat(i * 75 + 764 + seed) - 0.5),
		2 * (randFloat(i * 5678 + 3653 + seed) - 0.5),
		2 * (randFloat(i * 657 + 48464 + seed) - 0.5)
	);
	target.normalize();
	target.multiply(mult);
	target.multiplyScalar(amount * randFloat(i * 78 + 54 + seed));
}

export function jitterPositions(coreGroup: CoreGroup, options: JitterOptions) {
	const {amount, mult, seed} = options;
	coreGroup.points(_points);

	let i = 0;
	for (const point of _points) {
		jitterOffset(i, seed, mult, amount, _offset);

		point.position(_p);
		_p.add(_offset);
		point.setPosition(_p);
		i++;
	}
}