ios - UIView 的动画透视以向上/远离底部翻转一半

Question

我有一个 View ，我想像这里的插图一样翻转。

我目前的解决方案:

[UIView animateWithDuration:duration
                 animations:^{
                     [someView.layer setAffineTransform:CGAffineTransformMakeScale(1, 0)];
                 }];

这个解决方案的问题是，顶部边缘向下移动，而底部边缘向上移动。我希望顶部边缘保持不变，底部边缘向上/远离，如图所示。

编辑:就像那些猫门，哈哈。你用顶部的铰链将圆盘/方形表面推离你。

EDIT2:解决方案。

CGFloat someViewHeight = self.someView.frame.size.height;

CATransform3D baseTransform = CATransform3DIdentity;
baseTransform.m34 = - 1.0 / 200.0;
self.someView.layer.zPosition = self.view.frame.size.height * 0.5;
self.someView.layer.transform = baseTransform;

CATransform3D rotation = CATransform3DMakeRotation(- M_PI_2, 1.0, 0.0, 0.0);
CATransform3D firstTranslation = CATransform3DMakeTranslation(0.0, someViewHeight * 0.5, 0.0);
CATransform3D secondTranslation = CATransform3DMakeTranslation(0.0, - someViewHeight * 0.5, 0.0);

self.someView.layer.transform = CATransform3DConcat(CATransform3DConcat(firstTranslation, CATransform3DConcat(rotation, secondTranslation)), baseTransform);

我花了一段时间才弄明白 [UIView animateWithDuration:] 会为透视图或其他东西设置动画，所以动画会缩小 View 并做一些我无法解释的奇怪事情.所以我现在自己制作动画，每次都改变角度。

Answer 1

你的意思是这样的吗:

    [UIView animateWithDuration:3.0 animations:^{
        [someView.layer setAffineTransform:
         CGAffineTransformConcat(CGAffineTransformMakeScale(1.0f, .0001f), CGAffineTransformMakeTranslation(.0f, someView.frame.size.height*-.5f))];
    }];

这只是解决您描述的问题，要在图像上显示结果，您需要进行 3D 转换。

要进行 3D 转换，在您的情况下会变得非常棘手:

    CGFloat viewHeight = someView.frame.size.height; //needed later as this value will change because of transformation applied
    CATransform3D baseTransform = CATransform3DMakeTranslation(.0f, .0f, viewHeight*.5f); //put it towards user for rotation radius
    baseTransform.m34 = -1.0/200.0; //this will make the perspective effect
    someView.layer.zPosition = view.frame.size.height*.5f; //needed so the view isn't clipped
    someView.layer.transform = baseTransform; //set starting transform (no visual effect here)

    [UIView animateWithDuration:6.6 animations:^{
        someView.layer.transform = CATransform3DConcat(CATransform3DConcat(CATransform3DMakeRotation(-M_PI_2, 1.0f, .0f, .0f), CATransform3DMakeTranslation(.0f, viewHeight*.5f, .0f)) , baseTransform);
      //or to stay at the same center simply:
      //someView.layer.transform = CATransform3DConcat(CATransform3DMakeRotation(-M_PI_2, 1.0f, .0f, .0f) , baseTransform);
    }];

现在尝试一下。