ply-js

A compact, strongly-typed TypeScript library to read, write and analyze PLY (Polygon File Format) 3D meshes. Inspired by python-plyfile and focused on practical utilities for avatar and mesh processing: parsing, serialization, volume estimation, axis-aligned bounds and simple sizing helpers.

Features

• Full support for ASCII and common binary PLY encodings (little/big-endian).
• Read/write helpers for PLY headers and element data.
• Measurement helpers: AABB, centroid, cross-section perimeter, multiple volume estimators, and related utilities.
• High-level estimate helpers including per-scanner calibration support and an avatar/BMI estimation path.

Quick example

Read an ASCII PLY provided as lines:

import { readPlyFromLines } from 'ply-js';

const ply = readPlyFromLines(lines);
const vertexElement = ply.elements.find(e => e.name === 'vertex');
const faceElement = ply.elements.find(e => e.name === 'face' || e.name === 'polygon');

Estimate mass programmatically (with an optional calibration object):

import { estimateMass } from 'ply-js';

const result = estimateMass(points, faces, { objectType: 'avatar', calibration: myCalibration });
console.log(result.massKg, result.heightM);

Calibration

Per-scanner calibrations are supported and persisted as JSON. See CALIBRATION.md for instructions. Example scripts live in examples/ and are runnable via the package scripts.

pnpm calibrate        # run examples/calibrate.ts to create a calibration JSON
pnpm apply:calibration # run examples/apply-calibration.ts to demonstrate applying a saved calibration

Selected API

• readPlyFromLines(lines: string[]): PlyDocument
• readBinaryPly(buffer: Buffer): PlyDocument
• writePly(ply: PlyDocument): string
• writeBinaryPly(ply: PlyDocument): Buffer
• computeAABB(points: Point[]): AABB
• computeCentroid(points: Point[]): Point
• computeVolumeFromFaces(points: Point[], faces: Face[]): number
• estimateMass(points, faces, opts?): { massKg, heightM, volumes }

Refer to the dist typings and src files for full signatures and examples.

Contributing & License

See CONTRIBUTING.md for contribution guidelines. This project is licensed under the GNU General Public License v3 (GPL-3.0-or-later) — see COPYING and package.json for details.