Always use the redraw regions option when
building your project.
To improve rendering, it’s important to use the redraw regions
option when building your project. Using this option allows you
to see the regions that Flash Player is rendering and processing.
You can enable this option by selecting Show Redraw Regions in the
context menu of the debug version of Flash Player.
Note: The Show Redraw Regions option is not available in Adobe
AIR or in the release version of Flash Player. (In Adobe AIR, the
context menu is available only in desktop applications, but it has
no built-in or standard items such as Show Redraw Regions.)
The image below illustrates the option enabled with a simple
animated MovieClip on the timeline:
You can also enable this option programmatically, by using the flash.profiler.showRedrawRegions() method:
// Enable Show Redraw Regions
// Blue color is used to show redrawn regions
flash.profiler.showRedrawRegions ( true, 0x0000FF );
In Adobe AIR applications, this method is the only way to enable
the redraw regions option.
Use redraw regions to identify opportunities for optimization.
Remember that although some display objects are not shown, they
still consume CPU cycles because they are still being rendered.
The following image illustrates this idea. A black vector shape
covers the animated running character. The image shows that the
display object has not been removed from the display list and is
still being rendered. This wastes CPU cycles:
To improve performance, set the visible property
of the hidden running character to false or remove
it from the display list altogether. You should also stop its timeline.
These steps ensure that the display object is frozen and uses minimal
Remember to use the redraw regions option during the whole development cycle.
Using this option prevents you from being surprised at the end of
the project by unnecessary redraw regions and optimization areas
that have been missed.