rhesus | built templates with optional embedded Erb stuff

Reason it worked fine with Vue 2 lies in the fact Vue 2 is using different reactivity system based on Object.defineProperty API.

The same API is used by THREE.js a lot to add some non-writable and non-configurable properties to it's data structures

When object with such property was passed to Vue (by declaring it inside data for example), Vue just skipped such property resulting in stored value/object being non-reactive (as Vue could not detect property access while rendering the component template)

Vue 3 is using new reactivity system base on ES6 proxies.

This is pretty new and even that a lot of effort has been put into developing and testing it, issues like this will arise as people start migrating (And I completely agree with @Serg - Vue 3 is still new and unless you have skill and time to "live on the edge" you should wait a bit before migrating from Vue 2)

This new reactivity system doesn't play well with non-writable non-configurable properties on objects - you can find minimal reproducible example in this sandbox

1. Imho it is a bug and is reported to Vue@next repo
2. sandbox uses composition API but that doesn't matter as using reactive() is the same as declaring your variables inside data() function (Vue just do it automatically for you)

As said before, problem is in reactivity system. I'm not an expert on THREE.js but from what I know it doesn't make much sense to put the THREE data structures into Vue reactivity system - all point of reactivity is to detect data changes and re-render template when needed. THREE has its own rendering system and is usually using single HTML element so it makes no sense to trigger Vue re-render on THREE data structures change...

There are multiple ways to opt-out from Vue reactivity:

1. Use Object.freeze() on your objects. Not very useful in this case but good to know
2. Do not declare your variables in data() and assign the values in created()/mounted() hook (example bellow). You can assign them into component itself (this) if you need to access them in multiple methods or as a local variables (const/let) whenf you don't need it
3. When using Composition API, do not use reactive() on THREE data structures

NOTE: Even if they admit it is a bug, only way of fixing it is to leave such property and object it holds non-reactive (not putting Proxy around that object) so result will be same as opting-out of reactivity completely. But using this workaround also gives you faster and less memory hungry app as all the reactivity is not really that cheap

Example - creating non-reactive component properties

I'm afraid the problem originates from the creation of your camera:

this.camera = new Three.PerspectiveCamera(50, 1.686275 /*container.clientWidth/container.clientHeight*/, 0.01, 1000);

Why are you using the magical aspect number 1.686275 instead of the actual width/height ratio like you do on resize? This is giving you a different behavior before and after resizing.

This is my best guess at first glance, although I presume there are other instances of hard coded “magic numbers” in your app that need to be re-calculated based on the screen’s width and height. I couldn't possibly read through the 300 lines of code you posted. You should consider isolating the problem to create a minimal working example and add it to your question via a code snippet so we can see your code in action.

A simple way to do this would be to check if the inputs are equal to an empty string ("") using .equals(). For example:

As you can see from the API documentation, Firestore's query.get() returns a promise that resolves with a QuerySnapshot object. You're going to have to use that promise to wait for the query to complete, then iterate the documents in the QuerySnapshot object.

I suggest starting with the documentation to learn how queries work with Firestore, and see some examples.

Also, you're going to have to learn how JavaScript promises work with Cloud Functions. You must deal with the promise from the query and the promise from sendToDevice correctly, or the function won't work. See the documentation for details.