Keep the 3D Cube of Images Continue to Transition at the Same Side

I have used this tutorial to create a cube of images that move as a slideshow. https://webdevtrick.com/css-3d-cube-carousel/?unapproved=16788&moderation-hash=ec78aa2bd99b49552d07f0ec60049b18#comment-16788

see what is doing https://files.fm/u/s2ywz7my

I have managed this to be automatically moved using setInterval. When the cube reached the fourth image. It moved back to the first one.

jQuery file

<script>
        /** Code By Webdevtrick ( https://webdevtrick.com ) **/
        var $carousel = $('.carousel'),currentSlide, nextSlide;
        setInterval( function () 
        {
            currentSlide = $carousel.attr('data-slide');
            nextSlide = +currentSlide === 4 ? 1 : +currentSlide + 1;
            $carousel.attr('data-slide', nextSlide);
        }
        , 2000);
    </script>

I want the cube to continue sliding to the left and also as it is moving around itself.