I am using Android Studio to build a Android vr app with Google DayDream android vr sdk. I would like my users to be able to interact with the vr environment with their controllers that come with the vr headset.
But when I looked at the official documentation, I noticed that the controller support seems to be available only for Unity and Unreal. So I am wondering if I am still able to display a controller 3D model and its laser visualization with only the Android sdk. Link to controller support info for Unity and Unreal
If not, is it recommended that I use Unity for my Android vr app development.
I would recommend using the C++ version of the of the arm model that is included as part of Unreal. The arm model has no dependencies on Unreal code, so you should be able to integrate it into your app. If you are currently writing a java only app, this would require you to use the android NDK. Alternatively, you could look at porting the code to Java.
The arm model will only give you the position/orientation for the controller. If you do this, you will still need to render the controller and laser yourself in your application. You can pull the art assets from Unreal or Unity to do this.
Daydream development in Unity is fully supported, but you'll have to decide for yourself what is the best platform to use for your needs based on what type of development environment you prefer.