Parmanoir

Core Animation Starfield

Here's a little Core Animation sample with 3d layers.

Image:CoreAnimationStarfield.jpg
It looks better when moving ! :)

After learning that core animation doesn't like a root layer with a perspective transform, this sample sets up the perspective transform on a container layer, and stores the CATextLayer layers there. Works pretty well this time !

This uses preferredFrameSize to set the CATextLayer bounds, animates zPosition with CABasicAnimation and opacity with CAKeyframeAnimation to get a smooth transition from invisible, visible, invisible.

Coordinates

As we're going 3d, we don't work with (x,y) beetween ([0…frame width], [0 … frame height]) but with centered coordinates : [-width…width, -height…height]. This means our container layer needs to be centered in the view, or the 3d objects will appear to spring from the bottom left corner.

Issues

  • hit testing a layer doesn't work reliably.
  • the main layer is manually centered. Couldn't wrap my head around constraints.
  • how do you use Cocoa controls on a HUD window ? They don't look that good …

Image:iconZip.png CoreAnimationStarfield.zip

Core Animation

Jonathan Wight
2008 04 06

Nice code!

Runs like a dog on Macbook (1st gen) until you turn bloom filter off. Then runs really smoothly.

Subscribed!

Patrick Geiller
2008 04 06

Woops ! Maybe I should have Bloom disabled by default. But it's so much prettier ... :)

Chriss
2009 07 25

Very nice example ! Thanks a lot. Apple should provide that as sample code for CATextLayer.

tekka
2012 11 06

awesome,I'm learning your code


Follow me on Twitter
Planet Cocoa
Cocoa.fr

2011 02 22Distance field
2010 07 202Binding through NSApp
2010 05 122Forwarding invocations
2010 02 272Core Image black fringes
2010 02 21Quickest Way to Shell
2010 02 08Who's calling ?
2009 09 2138 ways to use Blocks in Snow Leopard
2009 08 182Bracket Mess
2009 08 124Taming JavascriptCore within and without WebView
2009 04 15Debugging with Activity Monitor
2009 03 25How Core Image Color Tracking works
2009 03 1510Custom NSThemeFrame
2009 03 10Which framework is running ?
2009 03 074CoreUI can paint pretty big
2009 02 18Localization with functions
2009 01 30Did you forget to nest alloc and init?
2009 01 16JSCocoa on the iPhone
2009 01 11Mixing WebView and JavascriptCore
2009 01 09Badge overflow
2009 01 09Find your Garbage Collection leaks with Instruments

Powered by MediaWiki