Development Environment Setup

This page will describe how to set a dev env for several OSes. The android build is described on a dedicated page.

=Third-Party Libraries and Tools=


 * OpenMW currently uses the following libraries:
 * OpenSceneGraph 3.4 - OpenGL rendering toolkit
 * SDL2 - input and windowing
 * MyGUI 3.2.1 - GUI toolkit
 * Bullet 2.86 - the physics engine
 * OpenAL or OpenAL soft - for sound playback
 * FFmpeg For sound decoding and BINK video playback.


 * OpenMW additionally uses the following tools:
 * CMake - used to manage the build process
 * Git - used as the source control management system

For those unfamiliar with Git, the Sphere RPG Engine group has a fairly useful short wiki page entitled "Git for the lazy". Make sure to also check out the GitLab FAQ.

MyGUI
By default, MyGUI will build with the Ogre3D platform enabled, but Ogre3D is not a hard dependency. If you do not want to have Ogre installed, then configure MyGUI with the dummy platform, and disable tools & demos:

OpenSceneGraph
It is recommended to use the OpenMW/osg fork of OpenSceneGraph. OpenMW still works with "vanilla" OpenSceneGraph, but may run at slightly lower frame rate.

Keep in mind the official OpenSceneGraph 3.6.3 release has a critical regression which causes major instabilities in OpenMW. Even if you don't want to use our fork, make sure to use a build linked against an older or a newer stable release (e.g. 3.4.1 or 3.6.4).

OSG plugins
OSG comes with numerous plugins, most of which are not required by OpenMW. If you install OSG from a package manager, then you will have tons of bloat on your system that OpenMW does not need (another reason to build your own).

Only the following plugins are required for OpenMW to function properly:

Texture formats:
 * osgdb_dds
 * osgdb_tga
 * osgdb_bmp
 * osgdb_jpeg
 * osgdb_png

.osg format support:
 * osgdb_osg.so
 * osgdb_serializers_osg.so

Note, the jpeg/png plugins will not be built unless you have 'libpng' and 'libjpeg' headers installed on your system.

If you are creating a release package, the library files for the plugins need to go in  /osgPlugins-.

When using the OSG git master (to be 3.6), or the OpenMW OSG fork, you can use the following cmake arguments to avoid unneeded plugins from being built:

-DBUILD_OSG_PLUGINS_BY_DEFAULT=0 -DBUILD_OSG_PLUGIN_OSG=1 -DBUILD_OSG_PLUGIN_DDS=1 -DBUILD_OSG_PLUGIN_TGA=1 -DBUILD_OSG_PLUGIN_BMP=1 -DBUILD_OSG_PLUGIN_JPEG=1 -DBUILD_OSG_PLUGIN_PNG=1 -DBUILD_OSG_DEPRECATED_SERIALIZERS=0

S3TC texture compression support
OpenMW requires S3TC texture compression support. If you are using a proprietary video driver, you will usually have S3TC support out of the box. With open-source drivers on Linux, you may need to install S3TC support separately. An indicator for missing S3TC support are completely white or pink textures.

On Ubuntu: sudo apt-get install libtxc-dxtn-s2tc0

=Windows=

Visual Studio 2013-2019 scripted way
This is the recommended method to build OpenMW on Windows. This script is kept updated and has fewer ways of going wrong than setting up your development environment manually. If you have issues, make sure to report them somewhere official, such as the OpenMW forums, as otherwise we won't know anything needs fixing.

What you need

 * Visual Studio 2013, 2015, 2017 or 2019 (Community edition is enough)
 * Make sure you've got the C++ toolset installed, which isn't necessarily installed by default.
 * In VS 2017/2019, this is called "Desktop development with C++" and is available under the workloads tab in the Visual Studio installer. This can be added during initial installation or alternatively afterwards by typing "Visual Studio Installer" into the start menu search and choosing to modify Visual Studio 2017.
 * In VS 2015, a similarly-named package is available and can be added during initial installation or afterwards by choosing to repair then modify your VS installation from the Windows Programs and Features menu.
 * VS 2013 should always come with C++ support.
 * MSYSGit or Git for Windows as it's also called ( if you have Chocolatey)
 * Other Git implementations will be sufficient to clone the OpenMW repo, but MSYSGit also provides the bash shell used to run the script.
 * Note that WSL does not work for this as the script needs to execute windows executables.
 * Note that a full Cygwin install does not work for this as it tries to emulate Unix file permissions, and the script was not written with this in mind.
 * 7-zip in your path
 * works if you have Chocolatey, but make sure you reload your shell or otherwise refresh your environment variables afterwards.
 * If you don't use Chocolatey, install 7zip like any other application, then use the instructions in this guide to add it to your path.
 * CMake in your path
 * for Chocolatey, but make sure you reload your shell or otherwise refresh your environment variables afterwards. If you'd rather CMake was in the path for all users instead of just the current one, swap  for.
 * If you don't use Chocolatey, install CMake like any other application, making sure to choose "Add CMake to the system PATH for all users" or "Add CMake to the system PATH for the current user" when offered.
 * There might be an issue with the version of PowerShell bundled with Windows 7, so if you're using Windows 7 and the script hangs, consider updating PowerShell. If this helps, please tell someone, as we're not sure if this affects everyone or just one person.
 * ~10GB of free space per build platform (32/64-bit), for all the build artefacts.
 * Time. Around an hour most likely for a full release or debug build.

What you do

 * Pick a directory to do this in.
 * Its path cannot contain spaces (this can't change until Qt can be installed with a path containing spaces).
 * Its path should either be short (e.g. ) or you should enable long file paths in your registry (for example by following this guide).
 * Clone the OpenMW repo.  (or your own fork of it).
 * Open a Git Bash shell in the repo.
 * Remember that other Bash implementations such as WSL or Cygwin won't work.
 * Run the following command:.
 * Substitute Win64 with Win32 if doing a 32-bit build.
 * 2019 can also be substituted with 2015 for VS2015 or 2017 for VS2017
 * This will only install the runtime resources for the Debug configuration, so while others will be available in Visual Studio, they won't run.
 * To install them for Release instead, add  to the command. (see Release Optimization )
 * To install them for RelWithDebInfo instead, add  to the command.
 * If we ever change the default, adding  will set up the Debug configuration.
 * Only one configuration can be set up per command invocation, so feel free to run it again with another configuration specified to get all the ones you need.
 * Wait for the build environment to be set up.
 * Go to the build folder that was just created ( if you've used VS 2019 and specified 64-bit) and open.
 * If you're using VS 2017 or VS 2019 and this Visual Studio bug hasn't been fixed yet, there's an extra step to work around it.
 * In Visual Studio, for each executable target you intend to use (e.g.,  ,   etc.), right click on it in the Solution Explorer and choose Properties to open its Property Pages.
 * At the top left of the popup, you'll see that Configuration is set to something. Changing this to All Configurations ensures that you won't have to repeat this for every single build type later.
 * In the left hand list, under Configuration Properties, there'll be a Debugging category. Select it.
 * In the right hand list, you'll see that Working Directory is set to . Change this to something else, then press Apply at the bottom right of the popup.
 * Change it back to  and then press Apply again.
 * Make sure the Configuration dropdown at the top of Visual Studio is set to the one you want to use.
 * Debug builds are slow, but the easiest to use with a debugger.
 * Release builds are fast, but cannot be effectively used with a debugger.
 * RelWithDebInfo builds are fast, and can be used with a debugger, but some lines may be executed in a different order to how they appear in the source code, and some may be skipped altogether, making debugging more difficult.
 * If you want to use Visual Studio's debugger, make sure you've set a startup project in the Solution Explorer by right clicking one and choosing Set as Startup Project. (The default startup project is  which doesn't have an executable as it's a meta project used to build all other OpenMW projects at once, so cannot be started.)
 * Develop.

If this doesn't work
First, double check that you've followed the instructions properly. Some common problems are in bold. If you still have issues, make sure to report them somewhere official, such as the OpenMW forums, as otherwise we won't know anything needs fixing.

Updating dependencies
Once in a while, the versions of dependencies listed in the script will be updated. For some of these, they can be updated just by running the script again. However, for some others, the process has not been automated yet. The rough steps to do so manually are as follows:


 * If you don't have any particular reason to keep the existing build directory (the  directory), simply delete it and use the script to regenerate it. You will get a new build environment using updated dependencies.
 * If you need to keep the build directory, the process is more involved:
 * Delete the directory the dependency was extracted to
 * Remove any lines mentioning the dependency from
 * Run the script again.

Release Optimization
Official builds are done with Link Time Optimization (LTO) turned on. As it is time-costly option, automatic builds and the instructions above do not have LTO enabled. It may affect performance. One PC user testing in Seyda Neen saw ~50fps without and ~150fps with LTO. Android might required different instructions to see performance increase.

Enabling LTO can be done by ticking a checkbox in the CMake GUI, or passing -DOPENMW_LTO_BUILD=1 on the command line.

NOTE: This can take a release build from half an hour to two hours, potentially trash debugability if using RelWithDebInfo, and definitely if actually using Debug.


 * Open the CMake GUI. This should show up if you type cmake gui into the Start menu.
 * Set the build directory to the one with your OpenMW solution file. It should pick up all the settings the build script set.
 * Tick the OPENMW_LTO_BUILD option (might be fastest to type LTO into the filter bar).
 * Press Generate.
 * VS will then ask to reload the solution.

From Discord #development Jan-2020 with AnyOldName3 and Capo

Previous versions of this guide
https://forum.openmw.org/viewtopic.php?f=6&t=4074 quick placeholder

https://gist.github.com/ananace/de7f30454e99b3952405

NMake 2013-2019 scripted way
This method is basically the same as the one above, but produces NMake Makefiles for those who want a more Unix-like development setup. You will need to choose and set up your own editor and debugger etc.

What you need

 * Everything required for the above method, except you can optionally exclude the Visual Studio GUI and only install the build tools.

What you do

 * Pick a directory to do this in.
 * Its path cannot contain spaces (this can't change until Qt can be installed with a path containing spaces).
 * Its path should either be short (e.g. ) or you should enable long file paths in your registry (for example by following this guide).
 * Clone the OpenMW repo.  (or your own fork of it).
 * Open a console capable of command-line C++ development in the Git repo.
 * The simplest way of achieving this is to open the start menu, locate the folder for your chosen Visual Studio release, and open a Development Command Prompt for your chosen architecture (e.g. x64 Native Tools Command Prompt to build 64-bit OpenMW on a 64-bit machine). You can then use  to navigate to the cloned repo.
 * Microsoft recommend against permanently setting up the necessary environment variables to have access to C++ tools as updates to those tools may break many things if you do.
 * Open a Git Bash shell from within the development console. If Git Bash is the only Bash shell you have installed, the command  should suffice.
 * Remember that other Bash implementations such as WSL or Cygwin won't work.
 * Remember that if you don't open Bash from within the development console, the necessary environment variables for tools to access NMake and the compiler won't be set.
 * Run the following command:.
 * Substitute Win64 with Win32 if doing a 32-bit build.
 * 2019 can also be substituted with 2015 for the build tools provided with VS2015 or 2017 for those from VS2017
 * This will only set up the Debug configuration. NMake is a single-configuration build system, so you only get one build type per set of Makefiles.
 * To set up Release instead, add  to the command.
 * To set up RelWithDebInfo instead, add  to the command.
 * If we ever change the default, adding  will set up the Debug configuration.
 * Even though only one configuration can be set up per command invocation, you can feel free to run it again with another configuration specified to get all the ones you need.
 * Use  to navigate to the build folder that was just created (  if you've used the build tools from VS 2019 and specified 64-bit and the Debug configuration).
 * Develop
 * Use  build a target. If no target name is specified, all will be built.

Visual Studio 2008/2010/2012/2013
Setting up a Windows development environment manually is not recommended. If one were to follow these instructions, it would not lead to a working OpenMW build. If you have experience setting up the required libraries (including the ones not listed here), you may be able to work around any issues, but it's also possible that you won't be able to. It is unlikely that trying is worth your time.

Tools

 * Visual Studio 2008/2010/2012/2013 - normal or free (C++) express versions. Note that if you use Visual Studio 2012 or newer you will have to build Qt yourself.
 * CMake: CMake at least v2.8, but grab the latest stable release.
 * Git - Our version control software: Git at least v1.8.x, but grab the latest stable release.

Libraries
(Needs updating, +osg)
 * Boost: Use the installer for your Visual Studio version and set the environment variable BOOST_ROOT to the .
 * Bullet Download bullet and build the BulletCollision, BulletDynamics and LinearMath projects. Make sure the Runtime library is set to "Multi-threaded Debug DLL (/MDd)" or "Multi-threaded DLL (/MD)" for the debug and the release configuration, respectively. Also "Enable Run-Time Type Information" has to be set to "Yes (/GR)". Afterwards put the libraries into the  folder, strip the ending off (like _vs2010) and set the environment variable BULLET_ROOT to the .
 * Freetype: Freetype2, and set the environment variable FREETYPE_DIR to the .
 * MyGUI: Download and build following compilation instructions and set the MYGUI_HOME environment variable.
 * OpenAL: Download OpenAL11CoreSDK and set the environment variable OPENALDIR.
 * Qt. Download the latest Qt4 version for your Visual Studio version and install the environment variable QTDIR. Example: qt-win-opensource-4.8.4-vs2010.exe
 * msinttypes Download and extract to your visual studio 'install_root\VC\include' directory and overwrite the files there. This will give you C99 compliant inttypes. This is only required for building FFmpeg and not required for Visual Studio 2012 or later.
 * FFmpeg Download and extract the dev and shared of ffmpeg. The latest builds don't work. A known working version is commit 1eabd71, available in the "previous versions" links on that page. The environment variable is FFMPEG_HOME. (Note: A later build ffmpeg-20120914-git-8bdba0b-win64 appears to work ok with openmw-0.30 without crashing)
 * SDL2 Download and extract the SDL2 VS "Development Libraries". SDL2-devel-2.0.1-VC.zip Then set the SDL2_LIBRARY variable to the location of the SDL2.dll file.

Once this is done, you're ready to get the source code.


 * Get the OpenMW Source code using GIT or Tortoise Git

Download and install all of these and make sure the environment (the system and Cmake) knows where they are. If you develop under a non-admin account, use System variables rather than User variables (in Control Panel->System and Security->System->System Properties->Advanced (tab)->Environment Variables). Add the following, adjusted to the paths in your system:

Check that PATH includes the path to git.exe for CMakeGUI to find it.

Bullet libraries won't be found by CMake if you didn't put the built libraries manually into \lib\Release\ as indicated above. Alternatively modify cmake\FindBullet.cmake to look for ${BULLET_ROOT}/lib.

Similarly, either set MYGUI_INCLUDE_DIRS and MYGUI_PLATFORM_INCLUDE_DIRS manually in CMakeGUI or modify cmake\FindMyGUI.cmake to look for ${MYGUISDK}/include/MYGUI.

Need to remove SDL2main.lib from VS->Properties->Configuration Properties->Linker->Additional Dependencies if you run into linking errors building owmlauncher. One way is to edit CMakeLists.txt so that SDL2_BUILDING_LIBRARY is set before running CMakeGUI. Another way is to set the SDL2_LIBRARY env variable instead of SDL2DIR as indicated above.

Running and using CMake
First, before opening Cmake, create a sibling directory called "OpenMW - build" next to the root "openmw" so that an out-of-source build can be done. This step is not needed if you're using CMakeGUI, as a separate build directory can be specified at the start.

This will create a Visual Studio solution which you can use to compile OpenMW. (Hint: If you are building a debug version, add /bigobj to openmw project in VS->Properties->Configuration Properties->C/C++->Command Line->Additional Options)

via Cygwin
Git is available on Windows via cygwin. Git can be used directly on Windows instead of grabbing source zip files from Gihub. The cygwin environment will allow you to use the same git command line commands as are recommended for the Linux environment. Note however that the cygwin version of CMake does not appear to support VS2008 as a valid target; therefore, cygwin can only be used for Git commands and a standard Windows command prompt should be used for invoking CMake.

via msysGit
There is also a stand-alone compiled package called msysgit. This will give you a Cygwin-like console with the git command, which you may find easier than via Cygwin.

via TortoiseGit
There is also a GUI git client for the one used to TortoiseSVN or TortoiseCVS which is called TortoiseGIT. It will give you a nice GUI inside the Windows explorer. This is the easy way.

via Eclipse
First of all, you need the egit plugin. Install it, restart eclipse, "file -> import -> git -> clone"

=Linux=

Arch
There is a development package available for OpenMW on the AUR. It can be found at.

Information about building packages from the Arch User Repository (AUR) can be found at the Arch wiki.

Key requirements
Because some dependencies of OpenMW are not in the Ubuntu repositories we made a development repository on Launchpad which provides packages for the missing dependencies.

To be able to install these packages you need to add the openmw Launchpad PPA by running:

and to make sure that the ppa will be used run:

Packages
You will need g++ in order to compile OpenMW.

To setup a build environment and install all dependencies type:

Debian Stretch
Debian Stretch has all the packages necessary to build OpenMW.

Install OpenMW dependencies
sudo apt-get install git libopenal-dev libopenscenegraph-3.4-dev \ libsdl2-dev libqt4-dev libboost-filesystem-dev libboost-thread-dev \ libboost-program-options-dev libboost-system-dev libboost-iostreams-dev \ libavcodec-dev libavformat-dev libavutil-dev libswscale-dev libswresample-dev \ libbullet-dev libmygui-dev libunshield-dev cmake build-essential \ libqt4-opengl-dev

Key requirements
Because some dependencies of OpenMW are not in the Fedora Workstation repositories, you need to enable RPMFusion free and non-free repositories which provide packages for the missing dependencies.

Packages
You will need g++ in order to compile OpenMW.

To setup a build environment and install all dependencies type:

Fetching the source
Download the source from the main downloads page:, or get the latest git snapshot:

With make
Note that this is an out-of-source build. Generally, this is the preferred method when working with cmake. This creates a regular makefile.

Now we can start compiling. Normally you can just run

but if you have multiple cores, you can decrease your compile time by doing this:

= macOS =

Prerequisites
You must have recent version (7.0 or higher) of Xcode & Xcode command line tools.

Miminal macOS version is determined by minimal Xcode version. Supported deployment target is 10.8.

CMake & pkg-config are required. You can install these via Homebrew:

$ brew install cmake $ brew install pkg-config

Dependencies
The easiest way to handle OpenMW dependencies is to use OpenMW-deps-Mac, which is what is used for official release builds. Either follow the instructions in that repository to build from source, or download the prebuilt dependencies here.

Qt
Supported Qt version for macOS builds is 5.5.1. Newer versions require C++11 to be enabled.

Note that you can install Qt from homebrew too but we previously had some issues with deployment of OpenMW binaries built against homebrewed Qt. It's completely fine if you don't intend to deploy to other machines, though.

$ brew install qt@5.5

It's recommended, however, to use package from Qt Project site if you're planning to deploy your builds to other machines.

Build
First of all you'll need to clone OpenMW source code, either from our main repository or from your fork:

$ git clone https://gitlab.com/OpenMW/openmw/

Then you can cd into source directory and look around. Please note that out-of-source build is recommended:

$ mkdir build $ cd build I assume that openmw & build directories are siblings. Call CMake:

$ cmake \ -D CMAKE_PREFIX_PATH="$PATH_TO_DEPENDENCIES_DIR;$PATH_TO_QT_INSTALLATION" \ -D CMAKE_OSX_SYSROOT="$MAC_OS_VERSION" \ -D DESIRED_QT_VERSION=5 \ -D CMAKE_BUILD_TYPE=Debug \ -D BUILD_MYGUI_PLUGIN=FALSE \ -G"Unix Makefiles" \ ../openmw/

Where $PATH_TO_DEPENDENCIES_DIR and $PATH_TO_QT_INSTALLATION are directories listed earlier in this guide. $PATH_TO_DEPENDENCIES_DIR</tt> is a directory like "openmw-deps" containing "lib" and "include" sub-directories, and $PATH_TO_QT_INSTALLATION</tt> is a path to a Qt 5.5.1 installation (for example ~/Qt/Qt5.5.1/5.5/clang_64/lib/cmake</tt>). Note that these paths must be absolute; if they are relative paths then the correct files will not be found.

$MAC_OS_VERSION</tt> is the version of macOS in the format macosx10.##</tt>. For instance, if you are running macOS 10.13 (High Sierra), $MAC_OS_VERSION</tt> would need to be set to macosx10.13</tt>.

You may need to include this line in the `cmake` arguments: -D SDL2_INCLUDE_DIR="$PATH_TO_DEPENDENCIES_DIR/include/SDL2" \</tt>.

You may need to brew install bullet</tt>.

Then build:

$ make

And try:

$ open OpenMW.app $ open OpenMW-CS.app

Or run binaries directly to see the output:

$ OpenMW.app/Contents/MacOS/openmw-launcher $ OpenMW.app/Contents/MacOS/openmw $ OpenMW-CS.app/Contents/MacOS/OpenMW-CS

Deployment
If you want to make a release build and deploy it, you must set CMake variable OPENMW_OSX_DEPLOYMENT</tt> to TRUE</tt>:

$ cmake \ -D CMAKE_PREFIX_PATH="$PATH_TO_DEPENDENCIES_DIR;$PATH_TO_QT_INSTALLATION" \ -D CMAKE_OSX_SYSROOT="$MAC_OS_VERSION" \ -D CMAKE_OSX_DEPLOYMENT_TARGET="10.9" \ -D DESIRED_QT_VERSION=5 \ -D CMAKE_BUILD_TYPE=Release \ -D BUILD_ESMTOOL=FALSE \ -D BUILD_MYGUI_PLUGIN=FALSE \ -D OPENMW_OSX_DEPLOYMENT=TRUE \ -G"Unix Makefiles" ../openmw/

If these instructions aren't up to date, refer to the CI scripts in the repo.

Build & package:

$ make package After this command completes, you'll have a *.dmg file in current directory. You can publish this file as OpenMW release, send it to your friend, etc.

Note that if you'll try to launch release versions of OpenMW.app or OpenMW-CS.app directrly from build directory they won't work, because they're built in deployment configuration when all dependencies are expected to be inside application bundle, but they're not until everything is packed in *.dmg.

Troubleshooting
If you experiencing configuration or build errors, or just in doubt, please refer to our Travis CI build script, it's proven to be working and should help you setup build environment on almost any compatible Mac with OS X 10.9 or higher (older versions could work too, but we're unable to test on them).

Umbrella script: https://gitlab.com/OpenMW/openmw/blob/master/.travis.yml

Dependency setup: https://gitlab.com/OpenMW/openmw/blob/master/CI/before_install.osx.sh

Build: https://gitlab.com/OpenMW/openmw/blob/master/CI/before_script.osx.sh

=Data=

For a detailed description of how to obtain the data files check Installation_Instructions.