plugins - Unity3d integration with android

Question

I need to create an android application which consists of parts written on Unity3d (animation and so on) and on AndroidSDK (by androidSDK I mean few activities written in java, manifest and resources)

In fact I already have those parts (At least mocks are ready=)) And I can't figure out how to communicate between them.

I've read a lot of articles about unity3d android integration (mostly about things called "plugins") and failed to understand how this staff works=( The main thing I understood (everyone exept official refs wrote about that) is that documentation about plugins is very poor... =)

The only way to communicate which I can understand is to make an intent (broadcast) from unity3d script (using AndroidJavaClass and AndroidJavaObject) so my activity (written in java) can handle it. But something tells me it's not the best solution...

What I read about the problem is that I need to use JNI (which is java native interface - WHY?!? - why do I need to use native code?)

Do I need to create some middle-level code on java which purpose is to communicate with my java activity, compile it using AndroidNDK and include into my Unity3d project as a plugin? How can I write that middle layer than? Do I need to use UnityPlayer instead of "Activity" as a base class and why?

Answer 1

Here is a tutorial on the basics of running Unity inside of a normal Android app.

There is a great tutorial on running Unity inside of Android Views. Once you get this up and running you can start embedding scenes easily anywhere in your App.

When you need to call into the Java Android app from Unity, you can add this code:

AndroidJavaClass unityPlayer = new AndroidJavaClass("com.unity3d.player.UnityPlayer"); 
AndroidJavaObject activity = unityPlayer.GetStatic<AndroidJavaObject>("currentActivity");

And then you can call any method you want on your activity through the activity AndroidJavaObject. Something like this:

activity.Call("yourFunctionName", parameters);