filament/third_party/OpenImageDenoise/doc/compilation.md

Building Open Image Denoise from Source

The latest Open Image Denoise sources are always available at the Open Image Denoise GitHub repository. The default master branch should always point to the latest tested bugfix release.

Prerequisites

Open Image Denoise currently supports 64-bit Linux, Windows, and macOS operating systems. In addition, before you can build Open Image Denoise you need the following prerequisites:

• You can clone the latest Open Image Denoise sources via:

  git clone --recursive https://github.com/OpenImageDenoise/oidn.git
  

• To build Open Image Denoise you need CMake 3.1 or later, a C++11 compiler (we recommend using Clang, but also support GCC, Microsoft Visual Studio 2015 or later, and Intel® C++ Compiler 17.0 or later), and Python 2.7 or later.

• Additionally you require a copy of Intel® Threading Building Blocks (TBB) 2017 or later.

Depending on your Linux distribution you can install these dependencies using yum or apt-get. Some of these packages might already be installed or might have slightly different names.

Type the following to install the dependencies using yum:

sudo yum install cmake
sudo yum install tbb-devel

Type the following to install the dependencies using apt-get:

sudo apt-get install cmake-curses-gui
sudo apt-get install libtbb-dev

Under macOS these dependencies can be installed using MacPorts:

sudo port install cmake tbb

Under Windows please directly use the appropriate installers or packages for CMake, Python, and TBB.

Compiling Open Image Denoise on Linux/macOS

Assuming the above prerequisites are all fulfilled, building Open Image Denoise through CMake is easy:

• Create a build directory, and go into it

  mkdir oidn/build
  cd oidn/build
  

  (We do recommend having separate build directories for different configurations such as release, debug, etc.).

• The compiler CMake will use by default will be whatever the CC and CXX environment variables point to. Should you want to specify a different compiler, run cmake manually while specifying the desired compiler. The default compiler on most Linux machines is gcc, but it can be pointed to clang instead by executing the following:

  cmake -DCMAKE_CXX_COMPILER=clang++ -DCMAKE_C_COMPILER=clang ..
  

  CMake will now use Clang instead of GCC. If you are OK with using the default compiler on your system, then simply skip this step. Note that the compiler variables cannot be changed after the first cmake or ccmake run.

• Open the CMake configuration dialog

  ccmake ..
  

• Make sure to properly set the build mode and enable the components you need, etc.; then type 'c'onfigure and 'g'enerate. When back on the command prompt, build it using

  make
  

• You should now have libOpenImageDenoise.so as well as a set of example applications.

Compiling Open Image Denoise on Windows

On Windows using the CMake GUI (cmake-gui.exe) is the most convenient way to configure Open Image Denoise and to create the Visual Studio solution files:

• Browse to the Open Image Denoise sources and specify a build directory (if it does not exist yet CMake will create it).

• Click "Configure" and select as generator the Visual Studio version you have (Open Image Denoise needs Visual Studio 14 2015 or newer), for Win64 (32-bit builds are not supported), e.g., "Visual Studio 15 2017 Win64".

• If the configuration fails because some dependencies could not be found then follow the instructions given in the error message, e.g., set the variable TBB_ROOT to the folder where TBB was installed.

• Optionally change the default build options, and then click "Generate" to create the solution and project files in the build directory.

• Open the generated OpenImageDenoise.sln in Visual Studio, select the build configuration and compile the project.

Alternatively, Open Image Denoise can also be built without any GUI, entirely on the console. In the Visual Studio command prompt type:

cd path\to\oidn
mkdir build
cd build
cmake -G "Visual Studio 15 2017 Win64" [-D VARIABLE=value] ..
cmake --build . --config Release

Use -D to set variables for CMake, e.g., the path to TBB with "-D TBB_ROOT=\path\to\tbb".

CMake Configuration

The default CMake configuration in the configuration dialog should be appropriate for most usages. The following list describes the options that can be configured in CMake:

• CMAKE_BUILD_TYPE: Can be used to switch between Debug mode (Debug), Release mode (Release) (default), and Release mode with enabled assertions and debug symbols (RelWithDebInfo).

• OIDN_STATIC_LIB: Builds Open Image Denoise as a static library (OFF by default). CMake 3.13.0 or later is required to enable this option. When using the statically compiled Open Image Denoise library, you either have to use the generated CMake configuration files (recommended), or you have to manually define OIDN_STATIC_LIB before including the library headers in your application.

• TBB_ROOT: The path to the TBB installation (autodetected by default).