CSS3 3D 旋转：透视如何工作？

Question

在鼠标移动后，我正在开发 3D bloc。我正在更新 CSS 值以创建 3D 效果。 基地看起来像：

document.addEventListener('DOMContentLoaded', function() {
  let mouseMove = function (e) {
    let el = e.currentTarget;
    let delta_x = parseFloat(e.offsetX / el.offsetWidth).toFixed(3)
    let delta_y = parseFloat(e.offsetY / el.offsetHeight).toFixed(3)

    var transform = "rotateY(" + ((delta_x - 0.5) * 50) + "deg) " +
        "rotateX(" + (-(delta_y - 0.5) * 50) + "deg)"
    var boxShadow = parseInt(-(delta_x - 0.5) * 8) +"px " + 
        parseInt(-((delta_y - 0.5) * 8) + 2) + 
        "px 4px rgba(34, 25, 25, 0.4);"

    el.setAttribute('style', 
                    "transform: " + transform + "; " + 
                    "box-shadow: " + boxShadow);
  }

  let els = document.getElementsByClassName("el")
  let len = els.length
  for(let i=0; i<len; i++) {
    let el = els[i]
    el.addEventListener("mousemove", mouseMove)
  }
}, false);

html, body, #wrapper { 
  height: 100%; 
  margin: 0; 
  padding: 0; 
}
#wrapper {
  background: #a4d24b;
  /*font-family: 'Open Sans', sans-serif; */
  font-weight: 400;
  font-size: 14px;
  display: flex;
  flex-wrap: wrap;
  perspective: 500px;
}
.container {
  position: relative;
  margin: auto;
  width: 20%;
  height: 40%;
  transition: all .25s;
  transform-origin: 50% 50%;
}
.container:hover {
  transform: translateZ(25px);
}
.el {
  height: 100%;
  background: #FFF; color: #000;
  box-shadow: 0 2px 4px rgba(34, 25, 25, 0.4);
}
.el:not(:hover) {
  transform: rotateY(0deg) rotateX(0deg) !important;
  box-shadow: 0 2px 4px rgba(34, 25, 25, 0.4) !important;
}

<div id="wrapper">
  <div class="container">
    <div class="el"></div>
  </div>
</div>

JS 的概念很简单：当鼠标在 bloc 上移动时，我得到了鼠标在 x 和 y 上的位置（以 % 为单位：位置 / bloc 大小） >.

• 对于 x (0 -> 1) 我将 transform 属性从 rotate: rotateY(-12deg) 移动到 rotate: rotateY(12deg)
• y (0 -> 1) 从rotate: rotateX(-12deg) 到rotate: rotateX(12deg) 也是如此
• 我还移动了 box-shadow（带有 x 和 y）以帮助可视化。

结果看起来不错，但是如果我给这个块添加背景，结果看起来很奇怪。

（与背景相同的代码）

document.addEventListener('DOMContentLoaded', function() {
  let mouseMove = function (e) {
    let el = e.currentTarget;
    let delta_x = parseFloat(e.offsetX / el.offsetWidth).toFixed(3)
    let delta_y = parseFloat(e.offsetY / el.offsetHeight).toFixed(3)

    var transform = "rotateY(" + ((delta_x - 0.5) * 50) + "deg) " +
        "rotateX(" + (-(delta_y - 0.5) * 50) + "deg)"
    var boxShadow = parseInt(-(delta_x - 0.5) * 8) +"px " + 
        parseInt(-((delta_y - 0.5) * 8) + 2) + 
        "px 4px rgba(34, 25, 25, 0.4);"

    el.setAttribute('style', 
                    "transform: " + transform + "; " + 
                    "box-shadow: " + boxShadow);
  }

  let els = document.getElementsByClassName("el")
  let len = els.length
  for(let i=0; i<len; i++) {
    let el = els[i]
    el.addEventListener("mousemove", mouseMove)
  }
}, false);

html, body, #wrapper { 
  height: 100%; 
  margin: 0; 
  padding: 0; 
}
#wrapper {
  background: #a4d24b;
  /*font-family: 'Open Sans', sans-serif; */
  font-weight: 400;
  font-size: 14px;
  display: flex;
  flex-wrap: wrap;
  perspective: 500px;
}
.container {
  position: relative;
  margin: auto;
  width: 20%;
  height: 40%;
  transition: all .25s;
  transform-origin: 50% 50%;
}
.container:hover {
  transform: translateZ(25px);
}
.el {
  height: 100%;
  background: #FFF url(https://images-na.ssl-images-amazon.com/images/M/MV5BMjQyODg5Njc4N15BMl5BanBnXkFtZTgwMzExMjE3NzE@._V1_SY1000_SX686_AL_.jpg);
  background-size: cover;
  background-position: 50% 50%; 
  color: #000;
  box-shadow: 0 2px 4px rgba(34, 25, 25, 0.4);
}
.el:not(:hover) {
  transform: rotateY(0deg) rotateX(0deg) !important;
  box-shadow: 0 2px 4px rgba(34, 25, 25, 0.4) !important;
}

<div id="wrapper">
  <div class="container">
    <div class="el"></div>
  </div>
</div>

现在，看起来只有顶部在工作，而底部并没有朝着好的方向发展。 （鼠标从左上角移动到右下角时的最佳再现）。

我做错了吗？还是视角问题？

---

更新 一些浏览器不喜欢下面的 CSS，如果你在上面移动鼠标时白框没有移动，只需将其删除。

.el:not(:hover) { transform: rotateY(0deg) rotateX(0deg) !important; box-shadow: 0 2px 4px rgba(34, 25, 25, 0.4) !important; }

Answer 1

您需要在转换后的元素的直接父级上应用透视。

我用透视图解决了：继承

document.addEventListener('DOMContentLoaded', function() {
  let mouseMove = function (e) {
    let el = e.currentTarget;
    let delta_x = parseFloat(e.offsetX / el.offsetWidth).toFixed(3)
    let delta_y = parseFloat(e.offsetY / el.offsetHeight).toFixed(3)

    var transform = "rotateY(" + ((delta_x - 0.5) * 50) + "deg) " +
        "rotateX(" + (-(delta_y - 0.5) * 50) + "deg)"
    var boxShadow = parseInt(-(delta_x - 0.5) * 8) +"px " + 
        parseInt(-((delta_y - 0.5) * 8) + 2) + 
        "px 4px rgba(34, 25, 25, 0.4);"

    el.setAttribute('style', 
                    "transform: " + transform + "; " + 
                    "box-shadow: " + boxShadow);
  }

  let els = document.getElementsByClassName("el")
  let len = els.length
  for(let i=0; i<len; i++) {
    let el = els[i]
    el.addEventListener("mousemove", mouseMove)
  }
}, false);

html, body, #wrapper { 
  height: 100%; 
  margin: 0; 
  padding: 0; 
}
#wrapper {
  background: #a4d24b;
  /*font-family: 'Open Sans', sans-serif; */
  font-weight: 400;
  font-size: 14px;
  display: flex;
  flex-wrap: wrap;
  perspective: 500px;
}
.container {
  position: relative;
  margin: auto;
  width: 20%;
  height: 40%;
  transition: all .25s;
  transform-origin: 50% 50%;
  perspective: inherit;
}
.container:hover {
  transform: translateZ(25px);
}
.el {
  height: 100%;
  background: #FFF url(https://images-na.ssl-images-amazon.com/images/M/MV5BMjQyODg5Njc4N15BMl5BanBnXkFtZTgwMzExMjE3NzE@._V1_SY1000_SX686_AL_.jpg);
  background-size: cover;
  background-position: 50% 50%; 
  color: #000;
  box-shadow: 0 2px 4px rgba(34, 25, 25, 0.4);
}
.el:not(:hover) {
  transform: rotateY(0deg) rotateX(0deg) !important;
  box-shadow: 0 2px 4px rgba(34, 25, 25, 0.4) !important;
}

<div id="wrapper">
  <div class="container">
    <div class="el"></div>
  </div>
</div>