CALayer transformation - anchorPoint problem - iphone

I work on a card flip animation with CoreAnimation. The layer I want to animation is a UIView with UIImageViews as subviews. The animation approach:
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"transform"];
animation.duration=2.0f;
animation.repeatCount=1;
animation.fromValue = [NSValue valueWithCATransform3D:CATransform3DMakeRotation(0.0, 0, 1, 0)];
animation.toValue = [NSValue valueWithCATransform3D:CATransform3DMakeRotation(M_PI, 0, 1, 0)];
animation.removedOnCompletion = NO;
animation.fillMode = kCAFillModeForwards;
[layer addAnimation:animation forKey:#"flip"];
The problem is that the anchor point of the layer seems to wrong because it animates the view at the point x = 0. But the anchor point of the layer has the value (0.5, 0.5)
Any suggestions?

Related

Flipping two UIView using CATransform3D

I have created Visiting Card which has Front view & back View. When i tap on the front view it should flip the UIView & show the back side of the View.
Here is Code which I am trying:
CATransform3D transform = CATransform3DMakeRotation(M_PI, 0, 1, 0);
transform.m34 = 1.0/700.0;
CABasicAnimation *rotation = [CABasicAnimation animationWithKeyPath:#"transform"];
rotation.fromValue = [NSValue valueWithCATransform3D:CATransform3DIdentity];
rotation.toValue = [NSValue valueWithCATransform3D:transform];
rotation.duration = DURATION;
CABasicAnimation *translation = [CABasicAnimation animationWithKeyPath:#"position"];
translation.fromValue = [NSValue valueWithCGPoint:CGPointMake(self.imageview.center.x,[[self.imageview superview] center].y-45)];
translation.toValue = [NSValue valueWithCGPoint:CGPointMake(_frame.origin.x+_frame.size.width/2,
_frame.origin.y+_frame.size.height/2)];
translation.duration = DURATION;
CABasicAnimation *translation = [CABasicAnimation animationWithKeyPath:#"position"];
translation.fromValue = [NSValue valueWithCGPoint:CGPointMake(self.imageview.center.x,[[self.imageview superview] center].y-45)];
translation.toValue = [NSValue valueWithCGPoint:CGPointMake(_frame.origin.x+_frame.size.width/2,
_frame.origin.y+_frame.size.height/2)];
translation.duration = DURATION;
CAAnimationGroup *group = [CAAnimationGroup animation];
group.animations = #[ translation, rotation ];
group.duration = DURATION;
group.delegate = self;
group.fillMode = kCAFillModeForwards;
group.removedOnCompletion = NO;
[layer addAnimation:group forKey:nil];
Above code works perfectly for single view. How to combine the 2nd view to get flipping from front & back effect.
Using Core Animation
You can add both front and back to a container view. The back view will have a 180 degree rotation around Y and the front will be just normal. Both layers will be single sided (by setting layer.doubleSided = NO;.
Then when you apply the rotation you would animate the rotation of the container view so that both front and back animate at the same time.
UIView transitions
Or you could just use the built in flip animation
transitionFromView:toView:duration:options:completion:
and pass either UIViewAnimationOptionTransitionFlipFromLeft or UIViewAnimationOptionTransitionFlipFromRight for the option.

move a CALayer (add animation)

well I have a CALayer layer and I would like to move it, with a CADisplaylink. Like :
layer.center=CGPointMake(layer.center.x + 10, layer.center.y + 10);
but I can't use center or position for the layer.Here is my problem, I want to make it move like it was a uiimageview.
To move layer try to use this method
-(void)moveLayer:(CALayer*)layer to:(CGPoint)point{
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"position"];
animation.fromValue = [layer valueForKey:#"position"];
animation.toValue = [NSValue valueWithCGPoint:point];
layer.position = point;
[layer addAnimation:animation forKey:#"position"];
}

The serrated(shake) image will be shown when rotating the image if i use CATransform3DMakeRotation

I have a problem with the image rotated.
The serrated(shake) image will be shown when rotating the image if i use CATransform3DMakeRotation(M_PI, 0, 0, -1.0) to make a animation with layer.
The backgroundView is added into another animation view (same as the backgroundView, but the direction is reverse).
The code is:
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"transform"];
animation.toValue = [NSValue valueWithCATransform3D:CATransform3DMakeRotation(M_PI , 0, 0, -1.0)];
animation.duration = 30;
animation.cumulative = YES;
animation.repeatCount = INT_MAX;
[backgroundView.layer addAnimation:animation forKey:#"animationOne"];
Thank you for your time.
The problem is fixed , to use the function can remove the serrate of image when rotating.
[self.layer setShouldRasterize:YES];

Why CABasicAnimation will send the layer's view to back and front?

There are two UIViews of similar size. UIView one (A) is originally on top of UIView two (B). When I try to perform a CABasicAnimation transform.rotation.y on A's layer:
CABasicAnimation *rotateAnimation = [CABasicAnimation animationWithKeyPath:#"transform.rotation.y"];
CGFloat startValue = 0.0;
CGFloat endValue = M_PI;
rotateAnimation.fromValue = [NSNumber numberWithDouble:startValue];
rotateAnimation.toValue = [NSNumber numberWithDouble:endValue];
rotateAnimation.duration = 5.0;
[CATransaction begin];
[imageA.layer addAnimation:rotateAnimation forKey:#"rotate"];
[CATransaction commit];
During the animation, the animating layer's UIView (A) will be:
sent back (A is suddenly behind B)
rotating ... passed second half of the animation
sent front (A is now on top of B again)
Is there a way to keep A on top of B for the whole animation period? Thanks!
UPDATE: project source is attached: FlipLayer.zip
The problem is a rotation around the Y axis will, in a true 3D compositing system, make layer A intersect with layer B, such that half of layer A should be visible and half should be behind layer B. CoreAnimation does not provide a true 3D compositing system. Instead it attempts to determine which layer is in front of which other layer, and renders it entirely without intersection. In your case, during the first half of the rotation CoreAnimation has decided that layer B is on top of layer A in the 3D space. The simplest solution is probably to set the zPosition of layer A to layer.bounds.size.width (default is 0) for the duration of the animation (or permanently, if it should always be on top).
If you want to set it only for the duration of the animation, you can add a second animation for the transform.translation.z key path. Here's your -flip method modified to use this:
- (IBAction)flip:(id)sender {
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"transform.rotation.y"];
CGFloat startValue = 0.0;
CGFloat endValue = M_PI;
animation.fromValue = [NSNumber numberWithDouble:startValue];
animation.toValue = [NSNumber numberWithDouble:endValue];
animation.duration = 5.0;
[imageOne.layer addAnimation:animation forKey:#"rotate"];
animation.keyPath = #"transform.translation.z";
animation.fromValue = [NSNumber numberWithFloat:imageOne.layer.bounds.size.width];
animation.toValue = animation.fromValue;
[imageOne.layer addAnimation:animation forKey:#"zPosition"];
}
Have you tried adding a [self.view bringSubviewToFront:imageA]; in your animation sequence?
You could try to translate on the z axis and bring A forward first. Perform the rotation and then set the z back to its starting value.
Also, you probably won't see any perspective on the rotation unless you set the .m34 property on the transform. Try something like this:
CATransform3D transform = CATransform3DIdentity;
transform.m34 = 1.0f / -300.0f;
transform = CATransform3DRotate(transform, 0.0f, M_PI, 0.0f);
CABasicAnimation *rotateAnimation = [CABasicAnimation
animationWithKeyPath:#"transform"];
rotateAnimation.fromValue = [NSValue
valueWithCATransform3D(CATransformIdentity)];
rotateAnimation.toValue = [NSValue valueWithCATransform3D(transform)];
rotateAnimation.duration = 5.0;
[imageA.layer addAnimation:rotateAnimation forKey:#"rotate"];
You transaction block is unnecessary.
Best Regards.

CABasicAnimation not changing its position property after animation completes

i am applying CABasicAnimation for position property of a layer it is animating well but after animation complete its coming back to original position how to avoid that and to make image to stay in animated position only?
There are a few different ways to solve this. My favorite is to set the object at the end of the animation, and use fromValue instead of toValue to create the animation. You can also set both fromValue and toValue to create this effect. ie
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"position"];
animation.duration = 1.0;
animation.fromValue = [NSValue valueWithCGPoint:startPoint];
animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
viewToAnimate.center = endPoint;
[viewToAnimate.layer addAnimation:animation forKey:#"slide"];
The other way to do this is to set yourself as the delegate and implement:
-(void)animationDidStop:(id)sender finished:(BOOL)finished {
viewToAnimate.center = endPoint;
}
You need to set the final position. If you only use the animation fromValue and toValue it will snap back to the original starting point. The animation uses a copy of the view/layer as it "plays" and then the animation will show the original view/layer when it finishes.
If you don't explicitly set it, it will appear to snap back, even though the view/layer never really moved.
startPoint and endPoint are CGPoints and myView is the UIView that is being animated.
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"position"];
animation.duration = .3;
animation.fromValue = [NSValue valueWithCGPoint:startPoint];
animation.toValue = [NSValue valueWithCGPoint:endPoint];
animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
[myView.layer addAnimation:animation forKey:#"position"];
myView.layer.position = endPoint; // Must set end position, otherwise it jumps back
To set the object at the end of the animation just write the code like this
#import <QuartzCore/QuartzCore.h>
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"position"];
animation.duration = 1.0;
animation.fromValue = [NSValue valueWithCGPoint:startPoint];
animation.timingFunction = [CAMediaTimingFunction functionWithName:easing];
animation.fillMode = kCAFillModeForwards; // This line will stop the animation at the end position of animation
animation.autoreverses = NO;
viewToAnimate.center = endPoint;
[viewToAnimate.layer addAnimation:animation forKey:#"slide"];
You can just set removedOnCompletion to NO if you want to preserve the final value. And don't forget to set the fillMode.
Swift 4+
animation.fillMode = .forwards;
animation.isRemovedOnCompletion = false
Objective-C
animation.fillMode = kCAFillModeForwards; //The receiver remains visible in its final state when the animation is completed.
animation.removedOnCompletion = NO;
If you look at the docs for addAnimation:forKey:, it says 'Typically this is implicitly invoked'. In other words, you're not supposed to call it directly. You're actually meant to do the following instead, which is even easier than setting from and to values, you simply set the values directly on the layer:
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"opacity"];
animation.duration = .3;
myLayer.actions = #{#"opacity": animation};
myLayer.opacity = 0;
This will fade a layer to zero opacity.