Camera Capture Native for Unity Android

This is an Android-native plugin for Unity to access the device cameras. Unity has a far more comfortable way of doing this with WebCamTexture and in most cases you should prefer that. However, sometimes there might be a need to access that process on a lower level either with the Android API or the native C++ code, for various reasons. This project provides these two points of access.

Inspiration

This project is heavily based on https://github.com/robsondepaula/unity-android-native-camera

Key differences include:

• The Android API and Android Native parts are joined into one single project now. This has implications when building, refer to the Building the Project section for more info.
• Native C++ part is moved to CMake 3.10.2 from ndk-build
• The Java part of the project is rewritten in Kotlin. This again has build implications.
• There is no release/debug choice in gradle.build now, please refer to the original project if you want that.

Making it work

Two main things are required to make it work: building the project itself and interfacing it with Unity.

Building the Project (important!)

Simply run the build from Android Studio and collect the aar artifact in the output.

Notice on Kotlin

Since the project relies on Kotlin, it introduces the additional dependency of kotlin stdlib that's necessary to make it work. To include it into the Unity project:

• In Android Studio expand "Additional Dependencies" and locate org.jetbrains.kotlin:kotlin-stdlib:<version>@jar
• Expand it and right-click on the library root, then choose "Show in Explorer"
• Copy the shown jar into Assets/Plugins/Android

This additional jar is always required in your Unity project to make Kotlin work.

Notice on native libraries

By default the native libraries are compiled into the aar as well, so you don't have to separately put anything else into the Unity project except the aar itself. Put the aar artifact into Assets/Plugins/Android and it should be ready to use.

However if you want to reduce the aar size and/or have more control over the native libraries, then:

• Make a build and collect the built native libraries in build/intermediates/stripped_native_libs/debug/out/lib. For example you might only want to copy the arm* variations and leave out the x86* ones. Put the native libraries into the Assets/Plugins/Android/Libs folder, where each lib goes to its corresponding folder, for example Assets/Plugins/Android/Libs/arm64-v8a, just as they are arranged by the build.
• Comment out the Native C++ part building section of the app/build.gradle and rebuild the project. Now the resulting aar won't have the native libraries included and should be significantly less in size. Copy it to Assets/Plugins/Android just like before.

Important: if you change the Java/Kotlin packaging of this library, remember to change the corresponding function names in RenderingPlugin.cpp.

The Unity Part

The additional setup is required on Unity part:

• The complementing Unity script for interacting with this library is available in the Unity folder of this repo. Copy it to anywhere in your Unity project.

• Copy the app/src/main/AndroidManifest.xml file to Assets/Plugins/Android to make Unity properly recognize the library

Important: if you change the Java/Kotlin packaging of this library, remember to change the corresponding strings in CameraPluginWrapper.cs and AndroidManifest.xml.