What is this 0 to 1 thing exactly? How could I rotate the layer absolutely to 170 degrees, for example?
CALayer* viewLayer = myView.layer;
CABasicAnimation* animation = [CABasicAnimation animationWithKeyPath:#"transform.rotation.z"];
animation.fromValue = [NSNumber numberWithFloat:0.0 * M_PI];
animation.toValue = [NSNumber numberWithFloat:1.0 * M_PI];
animation.duration = 1.0;
animation.cumulative = YES;
animation.repeatCount = 2;
animation.removedOnCompletion = NO;
animation.fillMode = kCAFillModeForwards;
[viewLayer addAnimation:animation forKey:#"transform.rotation.z"];
Not knowing an Cocoa, I would say that the toValue specifies 1.0Pi radian rotation. There are 2Pi radians in 360 degrees. Hence 1.0Pi represents 180 degrees. To get a 170 degree rotation I would set toValue as
animation.toValue = [NSNumber numberWithFloat:(170.0/180.0) * M_PI];
Related
I have created a circle using CAShapeLayer. I want to rotate this circle at fix centre. i'm using following code for animation. Using this code circle is rotating but not at a fix centre. Is centre keeps on changing. I don't want that to happen.
This is my code for animation
CABasicAnimation* rotationAnimation;
rotationAnimation = [CABasicAnimation animationWithKeyPath:#"transform.rotation.z"];
rotationAnimation.toValue = [NSNumber numberWithFloat: M_PI * 2.0 * rotations * 2.0 ];
rotationAnimation.duration = 10.0; // rotationAnimation.cumulative = YES;
rotationAnimation.repeatCount = 1.0;
rotationAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
[circle1 addAnimation:rotationAnimation forKey:#"rotationAnimation"];
Thanks
This will keep it inside rect.
[circle1 setAnchorPoint:(0.5,0.5)];
CGFloat angle = rotationAnimation.toValue;
CGFloat radius = someRadius;
CGPoint rotationCenter = CGPointMake(centerX,centerY);
circle1.frame = CGRectMake(rotationCenter.x + radius * cos(angle), rotationCenter.y + radius * sin(angle), circle1.frame.size.width, circle1.frame.size.height);
I've started using CATransform3D lately and it seems very nice. I just have 1 issue with the rotation though. I'm trying to rotate my view for 360˚ degrees to the right but if I just put pass 360 to CATransform3DRotate it doesn't work (It just doesn't move at all.)
Here's my code:
CALayer *layer = dock.layer;
CATransform3D r = CATransform3DIdentity;
r.m34 = 1.0 / -500;
r = CATransform3DRotate(r, DegreesToRadians(360.0f), 100.0f, 1.0f, 100.0f);
layer.transform = r;
Does anyone know how to fix this issue? Thanks in advance! :)
You can animate a layer through one (or more) full rotations around its Z axis by animating the layer's transform.rotation key path, like this:
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"transform.rotation"];
animation.duration = .25;
animation.fromValue = [NSNumber numberWithFloat:0];
animation.toValue = [NSNumber numberWithFloat:2 * M_PI];
[layer addAnimation:animation forKey:animation.keyPath];
You can animate around the X or Y axes using the key paths transform.rotation.x and transform.rotation.y. (The transform.rotation.z key path has the same effect as the transform.rotation key path.) You can apply multiple rotations, on separate axes, simultaneously.
Another way to do it, which probably works better if you want to rotate around an off-axis vector, is using a keyframe animation, like this:
CALayer *layer = [sender layer];
CATransform3D transform = CATransform3DIdentity;
transform.m34 = 1.0 / -50;
layer.transform = transform;
CAKeyframeAnimation *animation = [CAKeyframeAnimation animationWithKeyPath:#"transform"];
animation.values = [NSArray arrayWithObjects:
[NSValue valueWithCATransform3D:CATransform3DRotate(transform, 0 * M_PI / 2, 100, 1, 100)],
[NSValue valueWithCATransform3D:CATransform3DRotate(transform, 1 * M_PI / 2, 100, 1, 100)],
[NSValue valueWithCATransform3D:CATransform3DRotate(transform, 2 * M_PI / 2, 100, 1, 100)],
[NSValue valueWithCATransform3D:CATransform3DRotate(transform, 3 * M_PI / 2, 100, 1, 100)],
[NSValue valueWithCATransform3D:CATransform3DRotate(transform, 4 * M_PI / 2, 100, 1, 100)],
nil];
animation.duration = 2;
[layer addAnimation:animation forKey:animation.keyPath];
I am rotating a view with this:
CGAffineTransform rotatedTransform = CGAffineTransformRotate(CGAffineTransformIdentity, rotationValue);
I have an object which I want to spin around for about 320 degrees. Now Core Animation is clever and just rotates it as much as needed, doing that by rotating it with -40 degrees. So the object rotates the other way around with a shorter amount of movement.
I want to constrain it to rotate clockwise. Would I have to do that by changing animations in little steps, or is there an more elegant way?
The following snippet rotates a view called someView by using key-framed animation. The animation consists of 3 frames spread over 1 second, with the view rotated to 0º, 180º and 360º in the first, second and last frames respectively. Code follows:
CALayer* layer = someView.layer;
CAKeyframeAnimation* animation;
animation = [CAKeyframeAnimation animationWithKeyPath:#"transform.rotation.z"];
animation.duration = 1.0;
animation.cumulative = YES;
animation.repeatCount = 1;
animation.removedOnCompletion = NO;
animation.fillMode = kCAFillModeForwards;
animation.values = [NSArray arrayWithObjects:
[NSNumber numberWithFloat:0.0 * M_PI],
[NSNumber numberWithFloat:0.5 * M_PI],
[NSNumber numberWithFloat:1.0 * M_PI], nil];
animation.keyTimes = [NSArray arrayWithObjects:
[NSNumber numberWithFloat:0.0],
[NSNumber numberWithFloat:0.5],
[NSNumber numberWithFloat:1.0], nil];
animation.timingFunctions = [NSArray arrayWithObjects:
[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear],
[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear], nil];
[layer addAnimation:animation forKey:#"transform.rotation.z"];
If you're after counterclockwise animation, you should use negative values. For a slightly more basic animation, you can use CABasicAnimation:
CALayer* layer = someView.layer;
CABasicAnimation* animation;
animation = [CABasicAnimation animationWithKeyPath:#"transform.rotation.z"];
animation.fromValue = [NSNumber numberWithFloat:0.0 * M_PI];
animation.toValue = [NSNumber numberWithFloat:1.0 * M_PI];
animation.duration = 1.0;
animation.cumulative = YES;
animation.repeatCount = 1;
animation.removedOnCompletion = NO;
animation.fillMode = kCAFillModeForwards;
[layer addAnimation:rotationAnimation forKey:#"transform.rotation.z"];
I believe you have to give it another "key frame" if you will to give Core Animation the hint that it needs to go that direction.
Make sure and turn off easing, (at least for the end/beginning of the middle step) otherwise the animation will not look smooth.
How can we Move an Image 360 Degree from the starting point to the ending point?
Moving Image 360 Degree?
You can rotate a view, by some number of radians, regardless of whether it is less than a full rotation or many multiples of a full rotation, without having to split the rotation into pieces. As an example, the following code will spin a view, once per second, for a specified number of seconds. You can easily modify it to spin a view by a certain number of rotations, or by some number of radians.
- (void) runSpinAnimationWithDuration:(CGFloat) duration;
{
CABasicAnimation* rotationAnimation;
rotationAnimation = [CABasicAnimation animationWithKeyPath:#"transform.rotation.z"];
rotationAnimation.toValue = [NSNumber numberWithFloat: M_PI * 2.0 /* full rotation*/ * rotations * duration ];
rotationAnimation.duration = duration;
rotationAnimation.cumulative = YES;
rotationAnimation.repeatCount = 1.0;
rotationAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
[myView.layer addAnimation:rotationAnimation forKey:#"rotationAnimation"];
}
A 360 degree rotation in any axis leaves the view unchanged. So don't touch the image, and you're good to go!
You could use an animation function (CAValueFunction) for this too:
CABasicAnimation *rotationAnimation = [CABasicAnimation animationWithKeyPath:#"transform"];
rotationAnimation.duration = duration;
rotationAnimation.fromValue = [NSNumber numberWithFloat:0.0];
rotationAnimation.toValue = [NSNumber numberWithFloat:M_PI * 2.0];
rotationAnimation.valueFunction = [CAValueFunction functionWithName:kCAValueFunctionRotateZ];
rotationAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
[myView.layer addAnimation:rotationAnimation forKey:nil];
I want to rotate a layer continuously using byValue, but I can't make it work correctly.
I want to rotate by 6 degrees every second, to have a full rotation in 60 seconds.
If the initial rotation of the layer is 0, everything is OK.
The problem is when I try to set an initial fromValue. If I set the fromValue to 90 degrees, the animation will rotate from 90 to 90+6, then jump to 90+(90+6), animate, and jump again.
Any idea?
CABasicAnimation* animation = [CABasicAnimation animationWithKeyPath:#"transform.rotation.z"];
animation.fromValue = [NSNumber numberWithDouble:M_PI_2];
animation.byValue = [NSNumber numberWithDouble:6.0f*M_PI/180.0f];
animation.toValue = nil;
animation.fillMode = kCAFillModeForwards;
animation.cumulative = YES;
animation.additive = NO;
animation.repeatCount = 10000;
animation.removedOnCompletion = YES;
animation.duration = 1.0;
[myLayer addAnimation:animation forKey:#"transform"];
This works for me:
CABasicAnimation* animation = [CABasicAnimation animationWithKeyPath: #"transform"];
CATransform3D transform = CATransform3DMakeRotation (DegreesToRadians (90), 0, 0, 1);
animation.toValue = [NSValue valueWithCATransform3D: transform];
animation.duration = 60;
animation.cumulative = NO;
animation.repeatCount = 10000;
animation.removedOnCompletion = YES;