geom-sweep

Extrudes a shape along a path.

Installation

npm install geom-sweep

Usage

import sweep from "geom-sweep";

// Create a circle
const path = [];
for (let i = 0; i < 50; i++) {
  path.push([
    Math.cos((i / 50) * 2 * Math.PI),
    Math.sin((i / 50) * 2 * Math.PI),
    0,
  ]);
}
// Create a square
const shape = [
  [1, 1, 0],
  [-1, 1, 0],
  [-1, -1, 0],
  [1, -1, 0],
];

const geometry = sweep(path, shape, options);
// => {
//   positions: Float32Array(756),
//   normals: Float32Array(756),
//   uvs: Float32Array(504),
//   cells: Uint32Array(1512),
//   tangents: Float32Array(756),
//   frames: [{...}, {...}]
// }

API

sweep(path, shape, options): geometry

Parameters

• path: Array<[x, y, z]> – positions defining the path to extrude along

• shape: Array<[x, y, z]> – positions defining the swept shape

• options.radius: number (default: 1) - extruded geometry radius.

• options.closed: boolean (default: false) - is the path closed.

• options.closedShape: boolean (default: true) - is the shape path closed.

• options.caps: boolean (default: false) - add caps at the end.

• options.initialNormal: Array (default: null) - provide a starting normal for the frames. Default to the direction of the minimum tangent component.

• options.pathTangents: Array (default: undefined) - pass pre-computed path tangents.

• options.frames: Array<{ normal, tangent, bitangent }> (default: undefined) - pass pre-computed frenet serret frames.

Returns

geometry: { positions: TypedArray|Array, normals: TypedArray|Array, uvs: TypedArray|Array, cells: TypedArray|Array, tangents: TypedArray|Array, frames: Array<{ normal, tangent, bitangent }> } - the extruded geometry with tangents and frenet serret frames.

License

MIT. See license file.