I want to build an animated transition between two view controllers in iOS, resembling the "Box" transition in PowerPoint or the "Reflection" transition in Keynote.
You can see it here, at 2:10:
http://youtu.be/1fLQg5hFQQg?t=2m10s
What's the best way to do this?
Thanks!
That would be a complex animation to recreate. You'd need to use a CAAnimationGroup that grouped several different animations running at once. You'd want to animate a rotation around the y axis with the center of rotation lifted off the screen, on both the view controller that is animating away and the view that your are animating into place.
You would have to tweak the transform to make it draw with perspective (you add a small value to the .m34 record in the transform). That's because CA animations are orthographic by default (they don't show perspective.)
The reflections could be created using a special subclass of CALayer that lets you create duplicates of a layer. I'm blanking on the name of that layer subclass at the moment. You'd set up 1 duplicate with a scale of -1 on the y axis to flip it upside down, and a darkening effect. I've never done it myself, but I've seen several examples in books and online.
Related
Here is the iPad Simulator with four nested UIViews, drawing a custom background, and an inner UILabel. I am rotating the top UIView's CALayer, by getting it's layer and setting transform with a rotateY CATransform3D, animated on a separate thread (but the changes to transform are being sent on the main thread, naturally):
Note- this animation does not loop correctly, hence it appears to bounce.
The layers do animate as a whole, but curiously, the first child and it's descendants appear to be floating above the UIView with the transform applied!
The UIViews themselves are children in another UIView, which has a red background. There are no other transformations being applied anywhere else.
The positions for each UIView were set using setFrame initially at the start.
What is causing this strange behaviour, and how can I ensure the child UIViews transform with their parent, giving a flat appearance to the surface as a whole?
Well. Perhaps unsurprisingly I was doing something silly, but since I'd not used CALayer transforms before, I didn't know if things were acting up. I had overridden layoutSubviews on the UIViews I was creating, and the act of rotating the CALayer was triggering this call and then pushing the child components frame around, due to a bug.
The problem is that CALayers don't actually do 3D perspective by default. In order to do that you need to make a minor change to the layer's transform (which is of type CATransform3D)
You want to change the .m34 field of the transform to a small negative value. Try -1/200 to -1/500 as a starting range. If I remember correctly it should be the negative of 1 over the image height/width.
Change the .m34 property of the layer that you want to appear to "come off the page" and rotate in 3D. When you do that the Z setting of the layer does matter, and will both make closer layers bigger and also make layers that are further away disappear behind other things.
I suggest you do a Google search on "CATransform3D m34" for more information. There is a fair amount of information on the net about it.
I want to create a circular slider like below.
But i want two functionalities in addition.
1) I want to start the slider from any point,but in fig. it starts from 0.
2) I want to include multiple sliders in a single circular black plot.
I'm sharing the link of this project:
https://www.cocoacontrols.com/controls/circularsliderdemo
Can anyone help me to do these functionalities.
Thanks in advance.
Take a look at CAShapeLayer. You could create a path that is a full circle, and use the strokeStart and strokeEnd properties to only draw part of the circle. You could use core animation to animate between the beginning and the end.
There is an open source custom gesture recognizer on Github that is a one finger gesture recognizer. That would be a good start for detecting and responding to the twirl gesture that such a control would need. EDIT: It's called KTOneFingerRotationGestureRecognizer (link)
Those are some ideas to help get you started.
I have a project on github called iOS-CAAnimation-group-demo That includes a "clock wipe" animation. The clock wipe works by setting up a shape layer as the mask layer for an image view, installing a full-circle arc that's wide enough to completely fill a rectangular area, and then animate the strokeEnd property of the shape layer to reveal/hide the image view. The clock wipe is much more complex than what you need, but it would give you the seed of what you want. You'd use a shape layer with a much thinner line width, and you would use it as a content layer, not as a mask.
I need a animation like revolving electrons on three orbiter path i the middle of nucleus. I am currently using cocos2d 3.2V for developing my game. I tried to make revolving animation using bezier path but this work for quadrant of circle not make a complete circle animation. How can i achieve this kind of animation using cocos 2d?
Thanks in advance
The center is your parent node, you add the orbiting nodes to the parent with their position at an offset like 40x0, then rotate the parent and the child will rotate around it.
If you need different rotation speeds simply add multiple parent nodes to the center, one for each "planet".
If you want to make the movement an ellipsis you can cheat to some extent. You can have the parent move slightly up and down (or between any other two opposing points) synchronized with the rotation.
I have UIView with UIImageViews, UILabels, UITextView.
My goal is to transform the middle part so it would look like folding a piece of paper:
- top and bottom parts remain the same only they slide towards eachother
- middle part folds towards the screen
(as in Clear app: http://blog.massivehealth.com/post/18563684407/clear?cbe4fc38)
My idea was to first load whole view, then split into 4 parts, make middle two parts into CGImage and somehow animate them with perspective while simultaneously transforming top and bottom parts, so they slide towards eachother (in the end, middle two parts should become invisible).
I also should be able to unfold this view and scroll UITextView.
I'm not looking for a ready-to-go answer, just pointers towards correct solution.
I have came across CALayer, CABasicAnimation and CGImage, but yet don't know how to solve this one.
I think your approach is sound. Since you cannot apply a transform to part of a view, you have to split your container view into separate parts. You can use the CALayer method renderInContext: to render a view into a static image. You can then split this image into the parts you need, place the image parts over the original view (or replace the view with the image) and animate the images. When the animation has finished, reinstate the view in its new form.
A few pointers:
convert your UIView into an image: see this post; either you take 4 "snapshots" of your view, or:
1.2 you take one, then crop the resulting image (see here for cropping);
create a new view and add 4 CALayers as sublayers of self.layer; each layer has its contents property set to the corresponding UIImage;
animate the view layers as you need; have a look at this file from the Leaves framework to see how this could be done; basically, this code uses a CATransaction and transformations to animate a property of the layers (which in this case represents the position of one layer respect another), so that when that property value changes, the layers are redrawn accordingly.
Hope it helps.
I am a Core Animation newbie and I want to animate a pulsating blue dot very similar to what the Maps application does with the GPS position.
This is not in a map, and this doesn't use Map Kit. It's inside one of my own views (a UIImageView subclass actually), itself inside a UIScrollView.
I am just starting and I am hopeful for suggestions, best practices, perhaps sample code, to speed up my development.
Note a peculiar twist: the look (size) of the pulsating blue dot should preferably not depend on the zoom factor of the host view in its scroll view. I believe Map Kit behaves similarly.
The intent is to attract the user's attention to a specific tiny portion of a crowded image.
Thanks for any suggestion.
You could use two pre-generated images (one with "low light" and one with "high") and animate the transition between the two images. You'd want to use an ease-in curve similar to the map dot (speeds up as it gets brighter) and have it auto-reverse and repeat.
Alternatively, you could use a view with a blue-tinted shadow whose blur radius property is animated between zero and several pixels. With this latter approach, your custom-drawn dot could easily take the scale factor into account when drawing.