Object.assign( THREE.Vector3.prototype, {
    xyzFixedEq: function (vector,  digit) {
        if (this.x.toFixed(digit) - 0 == vector.x.toFixed(digit) - 0 &&
            this.y.toFixed(digit) - 0 == vector.y.toFixed(digit) - 0 &&
            this.z.toFixed(digit) - 0 == vector.z.toFixed(digit) - 0)
        {
            return true;
        }

        return false;
    }});

function tryAddDistinctVector3(array, item) {
    if (!vectorContains(array, item)) {
        array.push(item);
        return true;
    }

    return false;

    function vectorContains(array, item) {
        let index = array.findIndex(vector => vector.xyzFixedEq(item, 4));
        if (index > -1) {
            return true;
        }
        return false;
    }
}