更改滚动显示.js视口

我想在我的项目中使用ScrollReveal.js（https://github.com/julianlloyd/scrollReveal.js）和Isotope，以便在用户滚动时对对象进行动画处理，但页面必须有一个适合整个视口的固定div。这意味着页面实际上并没有滚动，用户在固定的div内滚动。

我正在寻找一种方法来更改滚动显示引用的视口。它不是跟踪页面的滚动，而是跟踪特定div 的滚动。

有什么想法吗？

提前致谢

<main id="mainn">
        <div class="isotope">
            <div data-sr='scale up 20%' class="item width2"></div>
            <div data-sr='scale up 20%' class="item width2 height2"></div>
            <div data-sr='scale up 20%' class="item width2"></div>
            <div data-sr='scale up 20%' class="item width2 height2"></div>
            <div data-sr='scale up 20%' class="item width2"></div>
            <div data-sr='scale up 20%' class="item width2"></div>
            <div data-sr='scale up 20%' class="item width2 height2"></div>
            <div data-sr='scale up 20%' class="item width2"></div>
            <div data-sr='scale up 20%' class="item width2 height2"></div>
            <div data-sr='scale up 20%' class="item width2"></div>
            <div data-sr='scale up 20%' class="item width2 height2"></div>
            <div data-sr='scale up 20%' class="item width2"></div>
            <div data-sr='scale up 20%' class="item width2 height2"></div>
            <div data-sr='scale up 20%' class="item width2"></div>
            <div data-sr='scale up 20%' class="item width2"></div>
            <div data-sr='scale up 20%' class="item width2 height2"></div>
            <div data-sr='scale up 20%' class="item width2"></div>
            <div data-sr='scale up 20%' class="item width2 height2"></div>
            <div data-sr='scale up 20%' class="item width2"></div>
            <div data-sr='scale up 20%' class="item width2 height2"></div>
            <div data-sr='scale up 20%' class="item width2"></div>
            <div data-sr='scale up 20%' class="item width2 height2"></div>
            <div data-sr='scale up 20%' class="item width2"></div>
            <div data-sr='scale up 20%' class="item width2"></div>
            <div data-sr='scale up 20%' class="item width2 height2"></div>
            <div data-sr='scale up 20%' class="item width2"></div>
            <div data-sr='scale up 20%' class="item width2 height2"></div>
            <div data-sr='scale up 20%' class="item width2"></div>
            <div data-sr='scale up 20%' class="item width2 height2"></div>
            <div data-sr='scale up 20%' class="item width2"></div>
            <div data-sr='scale up 20%' class="item width2 height2"></div>
            <div data-sr='scale up 20%' class="item width2"></div>
            <div data-sr='scale up 20%' class="item width2"></div>
            <div data-sr='scale up 20%' class="item width2 height2"></div>
            <div data-sr='scale up 20%' class="item width2"></div>
            <div data-sr='scale up 20%' class="item width2 height2"></div>
            <div data-sr='scale up 20%' class="item width2"></div>
            <div data-sr='scale up 20%' class="item width2 height2"></div>
            <div data-sr='scale up 20%' class="item width2"></div>
            <div data-sr='scale up 20%' class="item width2 height2"></div>
            <div data-sr='scale up 20%' class="item width2"></div>
            <div data-sr='scale up 20%' class="item width2"></div>
            <div data-sr='scale up 20%' class="item width2 height2"></div>
            <div data-sr='scale up 20%' class="item width2"></div>
            <div data-sr='scale up 20%' class="item width2 height2"></div>
            <div data-sr='scale up 20%' class="item width2"></div>
            <div data-sr='scale up 20%' class="item width2 height2"></div>
            <div data-sr='scale up 20%' class="item width2"></div>
            <div data-sr='scale up 20%' class="item width2 height2"></div>
            <div data-sr='scale up 20%' class="item width2"></div>
            <div data-sr='scale up 20%' class="item width2"></div>
            <div data-sr='scale up 20%' class="item width2 height2"></div>
            <div data-sr='scale up 20%' class="item width2"></div>
            <div data-sr='scale up 20%' class="item width2 height2"></div>
        </div>
    </main>

代码笔在这里： http://codepen.io/grahammcuk/pen/ogBNdp