html - CSS3 动画 - 流畅的无限动画

Question

我制作了一个小图像动画，其中图像的不透明度随时间变化。它运行流畅，但当最后一张图像达到 100% 时，它直接跳到 0%，没有任何过渡。

我已经尝试过 animation-direction: alternate for third image and delay for all image 但它对我不起作用。在延迟全部变为 0 之后，延迟仅在动画循环的第一步起作用。

这是我的 CSS

.rightside .img-container img.first {
  animation-name: first-image;
  animation-duration: 9s;
  animation-fill-mode: both;
  animation-iteration-count: infinite;
  /* animation-delay: -10s; */
}

.rightside .img-container img.second {
  position: absolute;
  top: 0;
  animation-name: second-image;
  animation-duration: 9s;
  animation-fill-mode: both;
  animation-iteration-count: infinite;
}

.rightside .img-container img.third {
  position: absolute;
  top: 0;
  animation-name: final-image;
  animation-duration: 9s;
  animation-fill-mode: both;
  animation-iteration-count: infinite;
  animation-timing-function: linear;
  /* animation-direction: alternate; */
}

@keyframes first-image {
  0% {
    opacity: 0;
  }
  33.3% {
    opacity: 1;
  }
  67% {
    opacity: 0;
  }
  100% {
    opacity: 0;
  }
}

@keyframes second-image {
  0% {
    opacity: 0;
  }
  33.3% {
    opacity: 0;
  }
  67% {
    opacity: 1;
  }
  100% {
    opacity: 0;
  }
}

@keyframes final-image {
  0% {
    opacity: 0;
  }
  33.3% {
    opacity: 0;
  }
  67% {
    opacity: 0;
  }

  100% {
    opacity: 1;
  }
}

HTML

        <div class="img-container">
          <img src="Images/Apple.png" class="first turn" alt="Image Here" />
          <img src="Images/Bee.png" class="second" alt="Image Here" />
          <img src="Images/Cat.png" class="third" alt="Image Here" />
        </div>

Answer 1

对此的经典方法是使用不同的延迟:

div {
  animation-name: all;
  animation-duration: 9s;
  animation-iteration-count: infinite;
  width: 100px;
  height: 100px;
  background-color: yellow;
}

.first {
  animation-delay: -3s;
  background-color: lightgreen;
}
.third {
  animation-delay: -6s;
  background-color: lightblue;
}


@keyframes all {
  0% {
    opacity: 0;
  }
  33.3% {
    opacity: 1;
  }
  67% {
    opacity: 0;
  }
  100% {
    opacity: 0;
  }
}

<div class="first"></div>
<div class="second"></div>
<div class="third"></div>