Need a mechanism to prevent some class properties being transformed to Vue data

[ericlogic]

Sometimes we don't need all of the class properties to be transformed to Vue data. Actually, I'm in trouble with three.js. When I define a Scene as a class property(It's a very common practice), It is transformed to Vue data and wrapped by Vue so it can't be rendered by three.js any more.

You might suggest that define it as a global variable. But it is not a "class style" way.

So. I suggest to provide a mechanism(maybe a @NonData decorator) to prevent some class properties being transformed to Vue data.