Use GLTF-transform merge command - node js script - node.js

Question

I want to use the gltf-transform command "merge" in my script and wrote something like this to merge two or more gltf files.
const { merge } = require('#gltf-transform/cli');
const fileA = '/model_path/fileA.gltf';
const fileB = '/model_path/fileB.gltf';
merge(fileA, fileB, output.gltf, false);
But nothing happened. No output file or console log. So I dont know where to continue my little journey.
Would be great when someone has a clue.
An alternative was...
const command = "gltf-transform merge("+fileA+", "+fileB+", output.gltf, false)";
exec(command, (error, stdout, stderr) => {
if (error) {
console.log(`error: ${error.message}`);
return;
}
if (stderr) {
console.log(`stderr: ${stderr}`);
return;
}
console.log(`stdout: ${stdout}`);
});
... but didnt work either and looks needless.

Answer 1

The #gltf-transform/cli package you're importing isn't really designed for programmatic usage; it's just a CLI. Code meant for programmatic use is in the /functions, /core, and /extensions packages.
If you'd like to implement something similar in JavaScript, I would try this instead:
import { Document, NodeIO } from '#gltf-transform/core';
const io = new NodeIO();
const inputDocument1 = io.read('./model_path/fileA.gltf');
const inputDocument2 = io.read('./model_path/fileB.gltf');
const outputDocument = new Document()
.merge(inputDocument1)
.merge(inputDocument2);
// Optional: Merge binary resources to a single buffer.
const buffer = doc.getRoot().listBuffers()[0];
doc.getRoot().listAccessors().forEach((a) => a.setBuffer(buffer));
doc.getRoot().listBuffers().forEach((b, index) => index > 0 ? b.dispose() : null);
io.write('./model_path/output.gltf', outputDocument);
This will create a single glTF file containing two scenes. If you wanted to merge the contents of both files into a single scene that would require moving some nodes around with the Scene API.

Answer 2

you can use gltf-transform/cli by using spawn.
// you should run `node #gltf-transform/cli/bin/cli.js`
const gltf_transform_cli_path = `your project's node_modules dir path${path.sep}#gltf-transform${path.sep}cli${path.sep}bin${path.sep}cli.js`
const normPath = path.normalize(gltf_transform_cli_path);
const command = `node ${normPath} merge ${fileA} ${fileB} output.gltf false`
const result = spawn(command)
and plus,
if you're going to use texture compressing using ktx(etc1s, usatc),
you've got to install ktx on your local.