OpenCV + Android + Unity

Question

I am looking for a way to use OpenCV in a Unity project and my target platform is an Android device.

I know that some assets exists on Unity asset store but I DO

Answer 1

Just to share what i had to do to compile the .so using C++17 with OpenCV 4.1.0 in Visual Studio.

First, i had to update my AndroidNDK via the VS-Installer to n15c. Using a separately downloaded NDK did not work for me. When starting to build, the NDK_ROOT will be printed so you can check if it's setup correctly.

Follow Pierre's Steps 1 and 2. In Linker->Input, i only set the library name in "Library Dependencies". I my case, that's opencv_java4, which is how the Linker likes it, derived from libopencv_java4.so

In Tab General set:

• Platform Toolset: Clang 5.0
• Configuration Type: Dynamic Library (.so)
• Target API: Nougat 7.0 (android-24) (others might be fine, too)
• Use of STL: LLVM libc++ shared (c++_shared)

In Tab Language set:

• Enable Run-Time Information: true
• C++ Language Standard: c++17 (-std=c++1z)

In Tab Code Generation set Enable C++ Exceptions to yes

In Tab Linker->Command Line add -lm -lz

I also had to set Not using Precompiled Headers in C/C++ -> Precompiled Headers. I don't think this is generally necessary though.

Hope this will be helpful for someone!