Method fromVector3

docs/app/js/sanddance-app.js:75739–75741

(v, order)

        this[3] = checkOrder(value);
    }
    fromVector3(v, order) {
        return this.set(v[0], v[1], v[2], Number.isFinite(order) ? order : this[3]);
    }
    fromArray(array, offset = 0) {
        this[0] = array[0 + offset];
        this[1] = array[1 + offset];