Basic glTF 2.0 optimization pipeline, using glTF-Transform.

basic_pipeline.ts

import { NodeIO } from '@gltf-transform/core';
import { ALL_EXTENSIONS, DracoMeshCompression } from '@gltf-transform/extensions';
import { center, dedup, inspect, quantize, weld } from '@gltf-transform/lib';
const draco3d = require('draco3dgltf');

const INPUT = '../glTF-Sample-Models/2.0/FlightHelmet/glTF/FlightHelmet.gltf';
const OUTPUT = './FlightHelmet.glb';
const MIN_DRACO_BYTES = 200000;

Promise.all([
	draco3d.createDecoderModule(),
	draco3d.createEncoderModule()
]).then(async ([decoder, encoder]) => {
	// Initialize I/O.
	const io = new NodeIO()
		.registerExtensions(ALL_EXTENSIONS)
		.registerDependencies({
			'draco3d.decoder': decoder,
			'draco3d.encoder': encoder,
		});

	// Read input.
	const document = io.read(INPUT);

	// Apply transforms.
	await document.transform(
		center(),
		dedup(),
		weld()
	);

	// Calculate size of geometry.
	let geometrySize = 0;
	for (const meshReport of inspect(document).meshes.properties) {
		geometrySize += meshReport.size;
	}

	// For large geometry, use Draco. For smaller geometry, just quantize.
	if (geometrySize >= MIN_DRACO_BYTES) {
		document.createExtension(DracoMeshCompression)
			.setRequired(true)
			.setEncoderOptions({
				decodeSpeed: 5,
				encodeSpeed: 5,
			});
	} else {
		await document.transform(quantize());
	}

	// Write output.
	io.write(OUTPUT, document);
});