backface-visibility

CSS 属性 backface-visibility 指定当元素背面朝向观察者时是否可见。

元素的背面是其正面的镜像。虽然在 2D 中不可见，但是当变换导致元素在 3D 空间中旋转时，背面可以变得可见。 （此属性对 2D 变换没有影响，它没有透视。）

/* Keyword values */
backface-visibility: visible;
backface-visibility: hidden;

/* Global values */
backface-visibility: inherit;
backface-visibility: initial;
backface-visibility: unset;

backface-visibility 属性可以指定为下面列出的值

visible

背面朝向用户时可见。

hidden

背面朝向用户时不可见。

visible | hidden

这个示例展示了一个拥有透明表面的立方体。

<table>
  <tr>
    <th><code>backface-visibility: visible;</code></th>
    <th><code>backface-visibility: hidden;</code></th>
  </tr>
  <tr>
    <td>
      <div class="container">
        <div class="cube showbf">
          <div class="face front">1</div>
          <div class="face back">2</div>
          <div class="face right">3</div>
          <div class="face left">4</div>
          <div class="face top">5</div>
          <div class="face bottom">6</div>
        </div>
      </div>
      <p>
        Since all faces are partially transparent,
        the back faces (2, 4, 5) are visible
        through the front faces (1, 3, 6).
      </p>
    </td>
    <td>
      <div class="container">
        <div class="cube hidebf">
          <div class="face front">1</div>
          <div class="face back">2</div>
          <div class="face right">3</div>
          <div class="face left">4</div>
          <div class="face top">5</div>
          <div class="face bottom">6</div>
        </div>
      </div>
      <p>
        The three back faces (2, 4, 5) are
        hidden.
      </p>
    </td>
  </tr>
</table>

/* Classes that will show or hide the
   three back faces of the "cube" */
.showbf div {
  backface-visibility: visible;
}

.hidebf div {
  backface-visibility: hidden;
}

/* Define the container div, the cube div, and a generic face */
.container {
  width: 150px;
  height: 150px;
  margin: 75px 0 0 75px;
  border: none;
}

.cube {
  width: 100%;
  height: 100%;
  perspective: 550px;
  perspective-origin: 150% 150%;
  transform-style: preserve-3d;
}

.face {
  display: block;
  position: absolute;
  width: 100px;
  height: 100px;
  border: none;
  line-height: 100px;
  font-family: sans-serif;
  font-size: 60px;
  color: white;
  text-align: center;
}

/* Define each face based on direction */
.front {
  background: rgba(0, 0, 0, 0.3);
  transform: translateZ(50px);
}

.back {
  background: rgba(0, 255, 0, 1);
  color: black;
  transform: rotateY(180deg) translateZ(50px);
}

.right {
  background: rgba(196, 0, 0, 0.7);
  transform: rotateY(90deg) translateZ(50px);
}

.left {
  background: rgba(0, 0, 196, 0.7);
  transform: rotateY(-90deg) translateZ(50px);
}

.top {
  background: rgba(196, 196, 0, 0.7);
  transform: rotateX(90deg) translateZ(50px);
}

.bottom {
  background: rgba(196, 0, 196, 0.7);
  transform: rotateX(-90deg) translateZ(50px);
}

/* Make the table a little nicer */
th, p, td {
  background-color: #EEEEEE;
  margin: 0px;
  padding: 6px;
  font-family: sans-serif;
  text-align: left;
}

• Using CSS transforms