Targeting Android

Android currently requires building the plugin from source.

In order to so, you will need to add this to your Project.Target.cs:

if (Target.Platform == UnrealTargetPlatform.Android)
{
	bCompileISPC = true;
	bOverrideBuildEnvironment = true;
}

You'll also need to integrate this PR (only tested on 5.2): https://github.com/EpicGames/UnrealEngine/pull/10746