The two main ways of reducing the size of the player are by changing the Active Build Configuration within Xcode and by changing the Stripping Level within Unity.
You can choose between the Debug and Release options on the Active Build Configuration drop-down menu in Xcode. Building as Release instead of Debug can reduce the size of the built player by as much as 2-3MB, depending on the game.
In Release mode, the player will be built without any debug information, so if your game crashes or has other problems there will be no stack trace information available for output. This is fine for deploying a finished game but you will probably want to use Debug mode during development.
The size optimizations activated by stripping work in the following way:-
These levels are cumulative, so level 3 optimization implicitly includes levels 2 and 1, while level 2 optimization includes level 1.
Note: Micro mscorlib is a heavily stripped-down version of the core library. Only those items that are required by the Mono runtime in Unity remain. Best practice for using micro mscorlib is not to use any classes or other features of .NET that are not required by your application. GUIDs are a good example of something you could omit; they can easily be replaced with custom made pseudo GUIDs and doing this would result in better performance and app size.
Stripping depends highly on static code analysis and sometimes this can't be done effectively, especially when dynamic features like reflection are used. In such cases, it is necessary to give some hints as to which classes shouldn't be touched. Unity supports a per-project custom stripping blacklist. Using the blacklist is a simple matter of creating a link.xml file and placing it into the Assets folder. An example of the contents of the link.xml file follows. Classes marked for preservation will not be affected by stripping:-
<linker> <assembly fullname="System.Web.Services"> <type fullname="System.Web.Services.Protocols.SoapTypeStubInfo" preserve="all"/> <type fullname="System.Web.Services.Configuration.WebServicesConfigurationSectionHandler" preserve="all"/> </assembly> <assembly fullname="System"> <type fullname="System.Net.Configuration.WebRequestModuleHandler" preserve="all"/> <type fullname="System.Net.HttpRequestCreator" preserve="all"/> <type fullname="System.Net.FileWebRequestCreator" preserve="all"/> </assembly> </linker>
Note: it can sometimes be difficult to determine which classes are getting stripped in error even though the application requires them. You can often get useful information about this by running the stripped application on the simulator and checking the Xcode console for error messages.
Yes. An empty project would take about 13 MB in the AppStore if all the size optimizations were turned off. This gives you a budget of about 7MB for compressed assets in your game. If you own an Advanced License (and therefore have access to the stripping option), the empty scene with just the main camera can be reduced to about 6 MB in the AppStore (zipped and DRM attached) and you will have about 14 MB available for compressed assets.
When they publish your app, Apple first encrypt the binary file and then compresses it via zip. Most often Apple's DRM increases the binary size by about 4 MB or so. As a general rule, you should expect the final size to be approximately equal to the size of the zip-compressed archive of all files (except the executable) plus the size of the uncompressed executable file.
Page last updated: 2011-11-07