沿锚点旋转 CATransformLayer

Question

构建一个由 6 面组成的立方体：每面都是一个 CALayer，然后每个都作为子视图添加到 (6) CATransformLayers（以启用 3d 转换）。 这 6 个 CATransformLayer 作为子视图添加到单个 CATransformLayer。

当旋转这个单独的 CATransformLayer 将整个立方体作为一个包进行旋转时，一切正常，我将锚点设置为 0,0，将锚点 Z 设置为立方体的中间：立方体完美地围绕其中心旋转。

问题： 我想“展开”当前侧的 4 个相邻侧，这意味着左侧、右侧、上方和下方的侧向用户旋转 90*，但仍坚持面向用户的一侧。

为此，例如我将当前边上方的anchorpointZ设置为0，将anchorpoint设置为(0.5,1)，这样anchorpoint基本上是公共边的中间。

设置立方体：

transformLayer = [CATransformLayer layer];
transformLayer.position = CGPointMake([UIScreen mainScreen].bounds.size.width/2,[UIScreen mainScreen].bounds.size.height/2);

CGRect layerRect = CGRectMake(0.0, 0.0, 150, 150); //frame rect for cube sides
CGPoint screenCenter = CGPointMake(self.transformLayer.bounds.size.width / 2, self.transformLayer.bounds.size.height / 2);

//side1
side1 = [CALayer layer];
side1.borderColor = [UIColor colorWithHue:0.6 saturation:1.0 brightness:1.0 alpha:1.0].CGColor;
side1.backgroundColor = [UIColor colorWithHue:0.6 saturation:1.0 brightness:1.0 alpha:0.8].CGColor;
side1.borderWidth = 2.0;
side1.cornerRadius = 30.0;
side1.frame = layerRect;
side1.position = screenCenter;


side1t = [CATransformLayer layer];
[side1t addSublayer:side1];


//side2
side2 = [CALayer layer];
side2.borderColor = [UIColor colorWithHue:0.25 saturation:1.0 brightness:1.0 alpha:1.0].CGColor;
side2.backgroundColor = [UIColor colorWithHue:0.25 saturation:1.0 brightness:1.0 alpha:0.8].CGColor;
side2.borderWidth = 2.0;
side2.cornerRadius = 30.0;    
side2.frame = layerRect;
side2.position = screenCenter;
//positioning
CATransform3D rotation = CATransform3DMakeRotation(M_PI/2, 0.0, 1.0, 0.0);
CATransform3D translation = CATransform3DMakeTranslation(150/2, 0.0, 150/-2 );
CATransform3D position = CATransform3DConcat(rotation, translation);
side2.transform = position;

side2t = [CATransformLayer layer];
[side2t addSublayer:side2];


//side3
side3 = [CALayer layer];
side3.borderColor = [UIColor colorWithHue:0.0 saturation:1.0 brightness:1.0 alpha:1.0].CGColor;
side3.backgroundColor = [UIColor colorWithHue:0.0 saturation:1.0 brightness:1.0 alpha:0.8].CGColor;
side3.borderWidth = 2.0;
side3.cornerRadius = 30.0;
side3.frame = layerRect;
side3.position = screenCenter;
//positioning
translation = CATransform3DMakeTranslation(0.0, 0.0, -150); //150
side3.transform = translation;

side3t = [CATransformLayer layer];
[side3t addSublayer:side3];


//side4
side4 = [CALayer layer];
side4.borderColor = [UIColor colorWithHue:0.2 saturation:1.0 brightness:1.0 alpha:1.0].CGColor;
side4.backgroundColor = [UIColor colorWithHue:0.2 saturation:1.0 brightness:1.0 alpha:0.8].CGColor;
side4.borderWidth = 2.0;
side4.cornerRadius = 30.0;
side4.frame = layerRect;
side4.position = screenCenter;
//positioning
rotation = CATransform3DMakeRotation(M_PI/2, 0.0, 1.0, 0.0);
translation = CATransform3DMakeTranslation(150/-2, 0.0, 150/-2);
side4.transform = CATransform3DConcat(rotation, translation);

side4t = [CATransformLayer layer];
[side4t addSublayer:side4];


//side5
side5 = [CALayer layer];
side5.borderColor = [UIColor colorWithHue:0.8 saturation:1.0 brightness:1.0 alpha:1.0].CGColor;
side5.backgroundColor = [UIColor colorWithHue:0.8 saturation:1.0 brightness:1.0 alpha:0.8].CGColor;
side5.borderWidth = 2.0;
side5.cornerRadius = 30.0;
side5.frame = layerRect;
side5.position = screenCenter;
//positioning
rotation = CATransform3DMakeRotation(M_PI/2, 1.0, .0, 0.0);
translation = CATransform3DMakeTranslation(0.0, 150/-2, 150/-2);
side5.transform = CATransform3DConcat(rotation, translation);

side5t = [CATransformLayer layer];
[side5t addSublayer:side5];


//side6
side6 = [CALayer layer];
side6.borderColor = [UIColor colorWithHue:0.0845 saturation:1.0 brightness:1.0 alpha:1.0].CGColor;
side6.backgroundColor = [UIColor colorWithHue:0.0845 saturation:1.0 brightness:1.0 alpha:0.8].CGColor;
side6.borderWidth = 2.0;
side6.cornerRadius = 30.0;
side6.frame = layerRect;
side6.position = screenCenter;
//positioning
rotation = CATransform3DMakeRotation(M_PI/2, 1.0, .0, 0.0);
translation = CATransform3DMakeTranslation(0.0, 150/2, 150/-2);
side6.transform = CATransform3DConcat(rotation, translation);

side6t = [CATransformLayer layer];
[side6t addSublayer:side6];


[self.transformLayer addSublayer:side1t];
[self.transformLayer addSublayer:side2t];
[self.transformLayer addSublayer:side3t];
[self.transformLayer addSublayer:side4t];
[self.transformLayer addSublayer:side5t];
[self.transformLayer addSublayer:side6t];

self.transformLayer.anchorPointZ = -150/2;
[self.layer addSublayer: transformLayer];

这部分不起作用。旋转（90°）是正确的，但侧面最终处于完全错误的位置，当前侧面前面的立方体大小的一半（z 坐标）并在 x-y 空间中覆盖了正面的一半，见截图

-(void)unfoldUpperSide {
[CATransaction begin];
[CATransaction setAnimationDuration: 3.0];
side5t.anchorPoint = CGPointMake(0.5, 0);
side5t.anchorPointZ = 0;
side5t.transform = CATransform3DMakeRotation(-M_PI/2, 1, 0, 0);
[CATransaction commit];
}

我整天都被困在这个问题上，希望有人能帮助我..！

Answer 1

您不需要为每一层制作一个 CATransformLayer，一个单独的 CATransformLayer 来容纳所有层就足够了，您仍然可以制作 3d 变换，因为 CATransformLayer 变换适用于其中层的所有锚点。

为什么你的个别边的旋转关闭是因为所有边的anchorPoint是0.5,0.5（即它们各自的中心，所以你围绕那个中心旋转）

您可以通过在两个所需方向上将层平移一半大小来解决此问题，同时旋转层，尽管最初有轻微的剪裁，这是下面的 osx 代码，只需将 NSColor 等更改为 UIKit 对应项。

-(void)cubeTest{

    float size = 100.0;

    CATransformLayer *transformLayer = [CATransformLayer layer];
    transformLayer.position = CGPointMake(cubeView.bounds.size.width/2,cubeView.bounds.size.height/2);

    CGRect layerRect = CGRectMake(0.0, 0.0, size, size); //frame rect for cube sides
    CGPoint screenCenter = CGPointMake(transformLayer.bounds.size.width / 2, transformLayer.bounds.size.height / 2);

    //side1
    CALayer *side1 = [CALayer layer];
    side1.borderColor = [NSColor colorWithHue:0.6 saturation:1.0 brightness:1.0 alpha:1.0].CGColor;
    side1.backgroundColor = [NSColor colorWithHue:0.6 saturation:1.0 brightness:1.0 alpha:0.8].CGColor;
    side1.borderWidth = 2.0;
    side1.cornerRadius = 30.0;
    side1.frame = layerRect;
    side1.position = screenCenter;
    [transformLayer addSublayer:side1];

    //side2
    CALayer *side2 = [CALayer layer];
    side2.borderColor = [NSColor colorWithHue:0.25 saturation:1.0 brightness:1.0 alpha:1.0].CGColor;
    side2.backgroundColor = [NSColor colorWithHue:0.25 saturation:1.0 brightness:1.0 alpha:0.8].CGColor;
    side2.borderWidth = 2.0;
    side2.cornerRadius = 30.0;
    side2.frame = layerRect;
    side2.position = screenCenter;
    //positioning
    CATransform3D rotation = CATransform3DMakeRotation(M_PI/2, 0.0, 1.0, 0.0);
    CATransform3D translation = CATransform3DMakeTranslation(size/2, 0.0, size/-2 );
    CATransform3D position = CATransform3DConcat(rotation, translation);
    side2.transform = position;
    [transformLayer addSublayer:side2];

    //side3
    CALayer *side3 = [CALayer layer];
    side3.borderColor = [NSColor colorWithHue:0.0 saturation:1.0 brightness:1.0 alpha:1.0].CGColor;
    side3.backgroundColor = [NSColor colorWithHue:0.0 saturation:1.0 brightness:1.0 alpha:0.8].CGColor;
    side3.borderWidth = 2.0;
    side3.cornerRadius = 30.0;
    side3.frame = layerRect;
    side3.position = screenCenter;
    //positioning
    translation = CATransform3DMakeTranslation(0.0, 0.0, -size); //size
    side3.transform = translation;
    [transformLayer addSublayer:side3];

    //side4
    CALayer *side4 = [CALayer layer];
    side4.borderColor = [NSColor colorWithHue:0.2 saturation:1.0 brightness:1.0 alpha:1.0].CGColor;
    side4.backgroundColor = [NSColor colorWithHue:0.2 saturation:1.0 brightness:1.0 alpha:0.8].CGColor;
    side4.borderWidth = 2.0;
    side4.cornerRadius = 30.0;
    side4.frame = layerRect;
    side4.position = screenCenter;
    //positioning
    rotation = CATransform3DMakeRotation(M_PI/2, 0.0, 1.0, 0.0);
    translation = CATransform3DMakeTranslation(size/-2, 0.0, size/-2);
    side4.transform = CATransform3DConcat(rotation, translation);
    [transformLayer addSublayer:side4];

    //side5
    CALayer *side5 = [CALayer layer];
    side5.borderColor = [NSColor colorWithHue:0.8 saturation:1.0 brightness:1.0 alpha:1.0].CGColor;
    side5.backgroundColor = [NSColor colorWithHue:0.8 saturation:1.0 brightness:1.0 alpha:0.8].CGColor;
    side5.borderWidth = 2.0;
    side5.cornerRadius = 30.0;
    side5.frame = layerRect;
    side5.position = screenCenter;
    //positioning
    rotation = CATransform3DMakeRotation(M_PI/2, 1.0, .0, 0.0);
    translation = CATransform3DMakeTranslation(0.0, size/-2, size/-2);
    side5.transform = CATransform3DConcat(rotation, translation);
    [transformLayer addSublayer:side5];

    //side6
    CALayer *side6 = [CALayer layer];
    side6.borderColor = [NSColor colorWithHue:0.0845 saturation:1.0 brightness:1.0 alpha:1.0].CGColor;
    side6.backgroundColor = [NSColor colorWithHue:0.0845 saturation:1.0 brightness:1.0 alpha:0.8].CGColor;
    side6.borderWidth = 2.0;
    side6.cornerRadius = 30.0;
    side6.frame = layerRect;
    side6.position = screenCenter;
    //positioning
    rotation = CATransform3DMakeRotation(M_PI/2, 1.0, .0, 0.0);
    translation = CATransform3DMakeTranslation(0.0, size/2, size/-2);
    side6.transform = CATransform3DConcat(rotation, translation);
    [transformLayer addSublayer:side6];

    transformLayer.anchorPointZ = -size/2;
    [cubeView setWantsLayer:YES];
    [cubeView.layer addSublayer:transformLayer];

    //animate

    CGFloat perspective = -1.0/10000.0;
    CABasicAnimation *transformAnimation = [CABasicAnimation animationWithKeyPath:@"transform"];

    CATransform3D transform = CATransform3DIdentity;
    transform.m34 = perspective;
    transformAnimation.fromValue = [NSValue valueWithCATransform3D:transform];

    transform.m34 = perspective;
    transform = CATransform3DRotate(transform, DEGREES_TO_RADIANS(90) , 1, 0, 0);

    transformAnimation.toValue = [NSValue valueWithCATransform3D:transform];

    transformAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
    transformAnimation.repeatCount = INFINITY;
    transformAnimation.duration = 10.0;
    [transformLayer addAnimation:transformAnimation forKey:@"RotateTheBox"];

    [self sideAnimation:side1 transform:CATransform3DTranslate(CATransform3DRotate(side1.transform, DEGREES_TO_RADIANS(90) , 1, 0, 0), 0, size/2, size/2)];
    [self sideAnimation:side3 transform:CATransform3DTranslate(CATransform3DRotate(side3.transform, DEGREES_TO_RADIANS(-90) , 1, 0, 0), 0, size/2, -size/2)];
    [self sideAnimation:side2 transform:CATransform3DTranslate(CATransform3DRotate(side2.transform, DEGREES_TO_RADIANS(90) , 1, 0, 0), 0, size/2, size/2)];
    [self sideAnimation:side4 transform:CATransform3DTranslate(CATransform3DRotate(side4.transform, DEGREES_TO_RADIANS(-90) , 1, 0, 0), 0, size/2, -size/2)];
    [self sideAnimation:side6 transform:CATransform3DTranslate(side6.transform, 0, 0, size)];//lower cap

}

-(void)sideAnimation:(CALayer*)side transform:(CATransform3D)transform
{
    CABasicAnimation *transformAnimation = [CABasicAnimation animationWithKeyPath:@"transform"];
    transformAnimation.toValue = [NSValue valueWithCATransform3D:transform];
    transformAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
    transformAnimation.repeatCount = INFINITY;
    transformAnimation.duration = 10.0;
    [side addAnimation:transformAnimation forKey:@"rotateSide"];
}