Await rhino3dm.js wasm import

Rhino Developer rhino3dm
1

By design, the rhino3dm javascript package has to be initialized (rhino3dm().then(rhino => { // do rhino stuff })) before being used. This is a wasm limitation and is all fine. You can even store the value in the .then ‘callback’ to run wasm functionality synchronously afterwards.

I have been suffering in silence, though, because the emscripten tool generates a promise-like module that you cannot await.

Finally came across this issue and wanted to share a workaround that just made my day.

import rhino3dm from 'rhino3dm'

// In some async context
await rhino3dm().then(rhino => {
    // Do something with rhino
    delete rhino['then']
}

This feels like the most sinful javascript I’ve ever seen but it works, even after multiple calls. I store the rhino module somewhere and run things synchronously from there.

2 Likes
Loading rhino3dm.js with dynamic routes
2

Thanks for the tip @Chuck_Driesler! I ran into this myself and it’s frustrating! We’ll have to experiment with the latest version of emscripten to see if it’ll resolve these issues for us as promised…

3

For sure! They actually just recently merged a fix for this. I’m not sure what it changes on your end, or if it’s live yet, but it looks promising.

4

Perfect, thanks! I was now struggling with this for days! Every time I tried to use await, it got stuck in limbo, but now it finally resolves!

Since I’m using SvleteKit with dynamic routes, I wasn’t able to make it work with the npm package, but if someone comes over the same problem, here was my solution with the help of @Chuck_Driesler s input, hope it might help someone

function initRhino() {
		// ref: https://github.com/mcneel/rhino3dm/blob/main/docs/javascript/RHINO3DM.JS.md
		// ref: https://discourse.mcneel.com/t/await-rhino3dm-js-wasm-import/101585

		return new Promise((resolve, reject) => {
			// Check if Rhino3dm is already loaded
			if (window.Rhino3dm) {
				console.log('Rhino3dm is already loaded.');
				resolve(window.Rhino3dm);
				return;
			}

			// Create and append the script
			const script = document.createElement('script');
			script.src = 'https://files.mcneel.com/rhino3dm/js/latest/rhino3dm.js';
			document.head.appendChild(script);

			script.onerror = () => {
				console.error('Failed to load the Rhino3dm script');
				reject(new Error('Failed to load the Rhino3dm script'));
			};

			script.onload = () => {
				console.log('Rhino3dm script loaded.');

				if (typeof window.rhino3dm !== 'function') {
					console.error('rhino3dm initialization function not found');
					reject(new Error('rhino3dm initialization function not found'));
					return;
				}

				let modulePromise = window.rhino3dm();
				if (modulePromise && modulePromise.then) {
					modulePromise.then((module) => {
						console.log('Rhino3dm module loaded.', module);
						delete module['then'];
						resolve(module); // Resolve the promise with the Rhino3dm module
					});
				} else {
					console.error('window.rhino3dm did not return a promise.');
					reject(new Error('window.rhino3dm did not return a promise.'));
				}
			};
		});
	}
2 Likes