title: How to add curvature to a card in flutter?
body: <p>So, I'm trying to develop a photobook app which shows the photos in front and back, Now I used card to flip but I need a animation to make it look natural like having a curvature for the card during the flip and the flip should be like turning a stiffened page.</p>
  <p>This is what I have tried</p>
  <pre><code>Widget __transitionBuilder(Widget widget, Animation&lt;double&gt; animation) {
    final rotateAnim = Tween(begin: pi, end: 0.0).animate(animation);
    return AnimatedBuilder(
      animation: rotateAnim,
      child: widget,
      builder: (context, widget) {
        final isUnder = (ValueKey(_showFrontSide) != widget.key);
        var tilt = ((animation.value - 0.5).abs() - 0.5) * 0.003;
        tilt *= isUnder ? -1.0 : 1.0;
        final value = isUnder ? min(rotateAnim.value, pi / 2) : rotateAnim.value;
        return Transform(
          transform: Matrix4.rotationY(value)..setEntry(3, 0, tilt),
          child: widget,
          alignment: Alignment.center,
        );
      },
    );
  }
  </code></pre>
  <p>But it produces the result as follows. Here the card depth is felt but need curvature at the center is it possible to do so?</p>
  <p>The result I need is like this image
  <a href="https://i.stack.imgur.com/phk24.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/phk24.png" alt="enter image description here" /></a></p>
  <p>The curvature at the center is it possible without curvature?</p>
  <p><a href="https://i.stack.imgur.com/wyW25.gif" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/wyW25.gif" alt="enter image description here" /></a></p>