Could not find UnityARCore when doing React Native Android build using Unity project

Question

I have a simple React Native app that is based on https://github.com/azesmway/react-native-unity

I use the <UnityView> component from this package to load my exported Unity project

If I download a simple Unity project - e.g. https://github.com/IVainqueur/flop-unity and then do an Android export then I can put the build into my unity/builds/android/unityLibrary directory. I then do an app build and I can successfully see the Unity project

However, if I want to use a more advanced Unity project such as the AR Foundation samples from https://github.com/Unity-Technologies/arfoundation-samples then I have a problem. I can do an Android export from Unity, put the files into the unity/builds/android/unityLibrary directory and then do an Android build of my React Native app

The React Native app build fails with the errors below. There seems to be a step missing that allows the React Native app to read the libs directory.

FAILURE: Build failed with an exception.

What went wrong:
Could not determine the dependencies of task ':unityLibrary:compileDebugAidl'.
Could not resolve all task dependencies for configuration ':unityLibrary:debugCompileClasspath'.
Could not find :arcore_client:.
Required by:
project :unityLibrary
Could not find :UnityARCore:.
Required by:
project :unityLibrary
Could not find :ARPresto:.
Required by:
project :unityLibrary
Could not find :unityandroidpermissions:.
Required by:
project :unityLibrary

My build.gradle file contains:

buildscript {
    ext {
        buildToolsVersion = "33.0.0"
        minSdkVersion = 22
        compileSdkVersion = 33
        targetSdkVersion = 33

        // We use NDK 23 which has both M1 support and is the side-by-side NDK version from AGP.
        ndkVersion = "23.1.7779620"
        
    }
    repositories {
        google()
        mavenCentral()
        flatDir {
            dirs "${project(':unityLibrary').projectDir}/libs"
        }
    }
    dependencies {
        classpath("com.android.tools.build:gradle")
        classpath("com.facebook.react:react-native-gradle-plugin")
    }

}

My settings.gradle file contains:

rootProject.name = 'projectName'
apply from: file("../node_modules/@react-native-community/cli-platform-android/native_modules.gradle"); applyNativeModulesSettingsGradle(settings)
include ':app'
includeBuild('../node_modules/@react-native/gradle-plugin')
include ':unityLibrary'
project(':unityLibrary').projectDir=new File('../unity/builds/android/unityLibrary')
include ':unityLibrary:xrmanifest.androidlib'

The file structure I have is:

Answer 1

You need to import :arcore_client, UnityARCore, ARPresto and unityandroidpermissions into your project the same way you include unity library.

Your settings.gradle file should look something like this:

rootProject.name = 'projectName'
apply from: file("../node_modules/@react-native-community/cli-platform-android/native_modules.gradle"); applyNativeModulesSettingsGradle(settings)
include ':app'
includeBuild('../node_modules/@react-native/gradle-plugin')
include ':unityLibrary'
project(':unityLibrary').projectDir=new File('../unity/builds/android/unityLibrary')
include ':unityLibrary:xrmanifest.androidlib'

include ':arcore_client'
project(':arcore_client').projectDir=new File('../unity/builds/android/arcore_client')

include ':UnityARCore'
project(':UnityARCore').projectDir=new File('../unity/builds/android/UnityARCore')

include ':ARPresto'
project(':ARPresto').projectDir=new File('../unity/builds/android/ARPresto')

include ':unityandroidpermissions'
project(':unityandroidpermissions').projectDir=new File('../unity/builds/android/unityandroidpermissions')

May also need to add:

 implementation(name: 'arcore_client', ext:'aar')
    implementation(name: 'UnityARCore', ext:'aar')
    implementation(name: 'ARPresto', ext:'aar')
  
    implementation(name: 'unityandroidpermissions', ext:'aar')

to build.gradle file dependencies.

May not be exactly that but should get you started. You may need to install addition .aar files that are in your unity folder.