flutter-unity-view-widget/README.md

flutter_unity_widget

Flutter unity 3D widget for embedding unity in flutter. Add a Flutter widget to show unity. Works on Android, iOS in works.

Installation

First depend on the library by adding this to your packages pubspec.yaml:

dependencies:
  flutter_unity_widget: ^0.1.4

Now inside your Dart code you can import it.

import 'package:flutter_unity_widget/flutter_unity_widget.dart';

Preview

Setup Project

For this, there is also a video tutorial, which you can find a here.

Add Unity Project

1. Create an unity project, Example: 'UnityDemoApp'.
2. Create a folder named unity in flutter project folder.
3. Move unity project folder to unity folder.

Now your project files should look like this.

.
├── android
├── ios
├── lib
├── test
├── unity
│   └── <Your Unity Project>    // Example: UnityDemoApp
├── pubspec.yml
├── README.md

Configure Player Settings

1. First Open Unity Project.

2. Click Menu: File => Build Settings

Be sure you have at least one scene added to your build.

3. => Player Settings

   Android Platform:

   1. Make sure your Graphics APIs are set to OpenGLES3 with a fallback to OpenGLES2 (no Vulkan)

   2. Change Scripting Backend to IL2CPP.

   3. Mark the following Target Architectures :

      • ARMv7 ✅
      • ARM64 ✅
      • x86 ✅

iOS Platform: 1. This only works with Unity version >=2019.3 because uses Unity as a library! 2. Other Settings find the Rendering part, uncheck the Auto Graphics API and select only OpenGLES3. 3. Depending on where you want to test or run your app, (simulator or physical device), you should select the appropriate SDK on Target SDK.

Add Unity Build Scripts and Export

Copy Build.cs and XCodePostBuild.cs to unity/<Your Unity Project>/Assets/Scripts/Editor/

Open your unity project in Unity Editor. Now you can export unity project with Flutter/Export Android or Flutter/Export IOS menu.

Android will export unity project to android/UnityExport.

IOS will export unity project to ios/UnityExport.

Android Platform Only

1. After exporting the unity game, open Android Studio and and add the Unity Classes Java .jar file as a module to the unity project. You just need to do this once if you are exporting from the same version of Unity everytime. The .jar file is located in the <Your Flutter Project>/android/UnityExport/lib folder
2. Next open build.gradle of flutter_unity_widget module and replace the dependencies with

    dependencies {
        implementation project(':UnityExport') // The exported unity project
        implementation project(':unity-classes') // the unity classes module you added from step 1
    }

3. Next open build.gradle of UnityExport module and replace the dependencies with

    dependencies {
        implementation project(':unity-classes') // the unity classes module you added from step 1
    }

4. Next open build.gradle of UnityExport module and remove these

    bundle {
        language {
            enableSplit = false
        }
        density {
            enableSplit = false
        }
        abi {
            enableSplit = true
        }
    }

iOS Platform Only

1. open your ios/Runner.xcworkspace (workspace!, not the project) in Xcode and add the exported project in the workspace root (with a right click in the Navigator, not on an item -> Add Files to “Runner” -> add the UnityExport/Unity-Iphone.xcodeproj file
2. Select the Unity-iPhone/Data folder and change the Target Membership for Data folder to UnityFramework
3. Add this to your Runner/Runner/Runner-Bridging-Header.h

#import "UnityUtils.h"

4. Add to AppDelegate.swift before the GeneratePluginRegistrant call:

InitArgs(CommandLine.argc, CommandLine.unsafeArgv)

5. Opt-in to the embedded views preview by adding a boolean property to the app's Info.plist file with the key io.flutter.embedded_views_preview and the value YES.

AR Foundation (ANDROID only at the moment)

If you want to use Unity for integrating Augmented Reality in your Flutter app, a few more changes are required:

1. Export the Unity Project as previously stated (using the Editor Build script).
2. Check if the exported project includes all required Unity libraries (.so) files (lib/\<architecture\>/libUnityARCore.so and libarpresto_api.so). There seems to be a bug where a Unity export does not include all lib files. If they are missing, use Unity to build a standalone .apk of your AR project, unzip the resulting apk, and copy over the missing .lib files to the UnityExport module.
3. Similar to how you've created the unity-classes module in Android Studio, create similar modules for all exported .aar and .jar files in the UnityExport/libs folder (arcore_client.aar, unityandroidpermissions.aar, UnityARCore.aar).
4. Update the build.gradle script of the UnityExport module to depend on the new modules (again, similar to how it depends on unity-classes).
5. Finally, update your Dart code build method where you include the UnityWidget and add isARScene: true,. Sadly, this does have the side effect of making your Flutter activity act in full screen, as Unity requires control of your Activity for running in AR, and it makes several modifications to your Activity as a result (including setting it to full screen).

Add UnityMessageManager Support

Copy UnityMessageManager.cs to your unity project.

Copy this folder JsonDotNet to your unity project.

Copy link.xml to your unity project.

Examples

Simple Example

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_unity_widget/flutter_unity_widget.dart';

class UnityDemoScreen extends StatefulWidget {

  UnityDemoScreen({Key key}) : super(key: key);

  @override
  _UnityDemoScreenState createState() => _UnityDemoScreenState();
}

class _UnityDemoScreenState extends State<UnityDemoScreen>{
  static final GlobalKey<ScaffoldState> _scaffoldKey =
      GlobalKey<ScaffoldState>();
  UnityWidgetController _unityWidgetController;

  Widget build(BuildContext context) {

    return Scaffold(
      key: _scaffoldKey,
      body: SafeArea(
        bottom: false,
        child: WillPopScope(
          onWillPop: () {
            // Pop the category page if Android back button is pressed.
          },
          child: Container(
            color: colorYellow,
            child: UnityWidget(
              onUnityViewCreated: onUnityCreated,
            ),
          ),
        ),
      ),
    );
  }

  // Callback that connects the created controller to the unity controller
  void onUnityCreated(controller) {
    this._unityWidgetController = controller;
  }
}

Communicating with and from Unity

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_unity_widget/flutter_unity_widget.dart';

class UnityDemoScreen extends StatefulWidget {

  UnityDemoScreen({Key key}) : super(key: key);

  @override
  _UnityDemoScreenState createState() => _UnityDemoScreenState();
}

class _UnityDemoScreenState extends State<UnityDemoScreen>{
  static final GlobalKey<ScaffoldState> _scaffoldKey =
      GlobalKey<ScaffoldState>();
  UnityWidgetController _unityWidgetController;
  bool paused = false;


  Widget build(BuildContext context) {

    return Scaffold(
      key: _scaffoldKey,
      body: Scaffold(
        key: _scaffoldKey,
        appBar: AppBar(
          title: const Text('Unity Flutter Demo'),
        ),
        body: Container(
            child: Stack(
          children: <Widget>[
            UnityWidget(
              onUnityViewCreated: onUnityCreated,
            ),
            Positioned(
              bottom: 40.0,
              left: 80.0,
              right: 80.0,
              child: MaterialButton(
                onPressed: () {

                  if(paused) {
                    _unityWidgetController.resume();
                    setState(() {
                      paused = false;
                    });
                  } else {
                    _unityWidgetController.pause();
                    setState(() {
                      paused = true;
                    });
                  }
                },
                color: Colors.blue[500],
                child: Text(paused ? 'Start Game' : 'Pause Game'),
              ),
            ),
          ],
        )),
      ),
    );
  }

  // Callback that connects the created controller to the unity controller
  void onUnityCreated(controller) {
    this._unityWidgetController = controller;
  }
}

API

• pause()

Known issues

• Android Export requires several manual changes
• Using AR will make the activity run in full screen (hiding status and navigation bar).