- Category: Windows
- Published on 15 May 2012
- Written by Thomas Hogarth
- Hits: 9006
Follows are details on usage of OpenSceneGraph from source packages. These are useful if you want to always stay up to date with the newest OSG sources from the SVN repository, or to use an OSG release that has no binaries. If you don't want this, you can probably use precompiled binaries from the Downloads page.
Compiling with Visual Studio .NET
(Note: These instructions are valid for Visual Studio .NET 2005 (8.0) and Visual Studio Express 2005 (see below), but they should also apply to Visual Studio .NET 2003 (7.0) or to Visual Studio .NET 2008 (9.0).)
The project files are set up so that if you have the dependencies in the same base directory as the OpenSceneGraph sources, then it will find them. Thus, the suggested directory structure is:
OpenSceneGraph-VERSION (replace VERSION by 2.8 or SVN or whatever)
OpenSceneGraph-VERSION\3rdParty (put the contents of the 3rdParty zip file in here)
In the OpenSceneGraph directory, see the Downloads page and download the sources for the version you're interested in, or check out the sources from the SVN repository using the SVN client of your choice (for example TortoiseSVN on Windows).
In the 3rdParty directory, see the Dependencies page and download the dependencies for your platform. Place them so that the bin, lib etc. directories are directly under OpenSceneGraph-VERSION\3rdParty .
Generating Project & Solution files with CMake
Once the sources and dependencies are in place you need to generate the Visual Studio solution and project files. This is done with CMake. Download it at http://www.cmake.org/HTML/Download.html.
Start the CMake GUI once it's installed, and select root OpenSceneGraph directory in the "Where is the source code" field. The same directory needs to be put into the "Where to build the binaries" field. If you like to do out-of-source builds, you can add \build to the end. Then click Configure.
You can then customize your build. The red lines in the CMake window indicate new variables that you may want to fill out or change, but most are optional. Some variables will be filled in automatically (such as ACTUAL_3RDPARTY_DIR, if you followed the directory structure above). I typically enable BUILD_OSG_EXAMPLES and set CMAKE_INSTALL_PREFIX to the OpenSceneGraph directory so that the binaries are installed in OpenSceneGraph\bin. You can also set it to somewhere else if you want to keep your source tree clean.
Note: In the permission-restricted environment of Windows Vista and later, do not set CMAKE_INSTALL_PREFIX to be a restricted folder like "Program Files". The make process will not be able to elevate permissions sufficiently to write to the destination, and will fail (typically while installing the first component, OpenThreads, with an error like "file INSTALL cannot copy file OpenThreads.dll").
Check if the dependencies you have are detected - if not fill in the variables manually. If you need to fill in some variables manually, you may need to show "Advanced" variables (with the drop-down at the top of the window) and make sure all relevant variables are set correctly for a given dependency. Any plugins or examples for which you don't have the dependencies will just not be part of the generated project files, which is cleaner than it was before (the projects would be there but just refuse to build, which resulted in lots of noise when building for things you knew would not build anyway).
Once your build configuration is to your liking, click Configure until the Generate button is enabled, then click that. Once it's done generating the project files, you can close CMake.
Building with Visual Studio
Open the generated OpenSceneGraph.sln file, which will be in the directory you entered under "Where to build the binaries" (eg. OpenSceneGraph\build), with Visual Studio. Select your desired build type (Debug, Release, RelWithDebugInfo, MinSizeRel) and press F7 for "Build Solution". Assuming everything builds correctly, you can then right-click on the INSTALL project and build that, which will copy the compiled files to the correct directories (based on what you set CMAKE_INSTALL_PREFIX to). Before that, the compiled files all reside in the build directory, and I don't recommend you use them from there.
Just to reiterate: Always build the INSTALL project. The locations where the files are copied to as part of the INSTALL target are the correct locations from where you should use them (bin\ for application executables and DLLs, lib\ for libraries, include\ for headers, and share\OpenSceneGraph\bin\ for example executables). See "Environment variables" below for some tips to set up your build environment for your own project to use the files from the correct locations.
A word of warning, the first time you compile from source it will take some time. After that, if you update an SVN checkout for example, it will compile incrementally (only what changed) so that's quite a bit faster.
Always regenerate after updates
You should regenerate the project files with CMake each time you update from SVN or update to a newer snapshot of the source code. That will make sure that a) any new build configuration options added to the CMake build files will be taken into account, and b) any new files will be included in the VS projects and compiled correctly. You can regenerate the build files by just opening the root CMakeLists.txt in the CMake GUI and setting the build directory to the same thing you had before (OpenSceneGraph\build, for example), that way any settings you had made will still be there. Just click Configure then Generate, open the OpenSceneGraph.sln and build.
If have the 3rdparty libraries installed, the BUILD_OSG_PLUGINS is ON in your CMake file and the FREETYPE_LIBRARY_DEBUG path is found it might still happen that the project files for Freetype plugins or not built. Select "Show Advanced Values" in CMake and copy the directory found in FREETYPE_INCLUDE_DIR to FREETYPE_INCLUDE_DIR_freetype2 and FREETYPE_INCLUDE_DIR_ft2build.
Cleanup the CMake cache
Finally, note that from time to time, to see new settings, you will need to delete the CMakeCache.txt file in the build directory, which will also erase your settings... This should be rare though.
Using Visual Studio Express 2005/2008
Visual Studio Express is a free Microsoft development system, a complete Visual Studio based on Visual Studio .NET 2005/2008, with all the features of VS 6 (debugger, icon designer, MS interface developer) . The download is free but a pretty large download; the license is perpetual but MS reserve the right to charge after Nov 2006. You can also download C#, J# and other studio components. Download Visual Studio Express from this page. Important: If you choose to use Visual Studio Express 2005, you will need to download the Platform SDK separately to provide some needed libraries.
See the instructions for Visual Studio .NET above to compile OpenSceneGraph with Visual Studio Express 2005/2008.
All in all it works as well as the commercial version (Visual Studio .NET 2005/2008).
Note that the Express Edition does not include MFC, so any example written for MFC will fail to build (currently, osgviewerMFC). There is now an option in the CMake setup to disable building the MFC example, which is the default, so that takes care of that.
Extensionless headers and syntax highlighting on Visual Studio 2003/2005/2008
In the OSG sources, in the PlatformSpecifics\Windows directory, there is a text file VisualStudio_Syntax_Highlighting.txt in which you can find instructions to get syntax highlighting on extensionless header files. It basically says:
Go to Tools-Options, then Text Editor-File Extension, check "Map Extensionless Files To" at the bottom and select "Microsoft Visual C++" in the list to the right.
Starting a new project
There are two basic ways to start a new project using the OSG.
Create a new solution and project, and add the OSG libs as dependencies
- Keeps everything separate, you can keep a tight control over the files in your project.
- If your own project is in SVN, it won't conflict with the OSG SVN.
- It's easy to distribute your project.
- If you need to modify the OSG or look something up, you need to open the OSG's workspace/solution separately.
I normally start the project by copying OpenSceneGraph\applications\osgViewer\osgViewer.cpp into my new project's src directory, and compiling that. If that doesn't compile and run, there's a problem. See "Environment Variables" below for how to set up the compiler's include and library search paths easily.
Create a project directly in the OSG workspace / solution
- If you have to modify OSG itself for your project, the Visual Studio dependency check will recompile what is needed automatically.
- You can quickly switch from the project on which you're working to the OSG code itself.
- You can examine code for any src/example easily.
- Your OSG workspace/solution will quickly become crowded once you start adding lots of your projects to it (as if it wasn't enough already...).
- When you regenerate the build files with CMake, you will have to re-add your project(s) to it.
- It's hard to separate your project from the OSG for distribution, so the other way is "cleaner".
- You can't keep your project in SVN if your OSG directories are also from SVN, unless you copy your project's files somewhere else, in which case why don't you just use the first method instead of having to do both?
I guess you can see that I don't recommend this way of doing. The OSG workspace/solution is already so big as it is, I think it's best to keep your mind uncluttered by creating a separate project for your own stuff. The rest of this guide is based on using the first option.
If you select the first method, a way to simplify things and to make your project files work on multiple different machines is to use some standard environment variables. I use the following:
OSG_ROOT points to the base of the OSG file structure (the directory that contains include, src etc. subdirectories)
OSG_BIN_PATH = %OSG_ROOT%\bin
OSG_INCLUDE_PATH = %OSG_ROOT%\include
OSG_LIB_PATH = %OSG_ROOT%\lib
OSG_SAMPLES_PATH = %OSG_ROOT%\share\OpenSceneGraph\bin
OSG_FILE_PATH = ???\OpenSceneGraph-Data-X.X
Then, add %OSG_BIN_PATH% and %OSG_SAMPLES_PATH% to your PATH environment variable. That way, not only can you run examples easily, but the latest DLLs will always be found. When starting an application, Windows looks for the required DLLs first in the executable's directory, then in the PATH.
Make sure you restart Visual Studio if it was open when you added/changed these environment variables, so that it picks up te changes.
In your project's properties, use those environment variables to get Visual Studio to find the OSG libraries. Here are the settings I use:
Properties - C/C++ - General - Additional Include Directories = $(OSG_INCLUDE_PATH)
Properties - C/C++ - Preprocessor - Preprocessor Definitions = WIN32;_WIN32;NDEBUG
Properties - Linker - General - Additional Library Directories = $(OSG_LIB_PATH)
Properties - Linker - Input - Additional Dependencies = (any OSG library your project needs - for example: osg.lib osgGA.lib osgDB.lib osgViewer.lib osgText.lib osgUtil.lib OpenThreads.lib)
Remember to do the same thing in your project's Debug configuration, but add a d to the end of the OSG and OpenThreads library names (osg.lib becomes osgd.lib and so on). Also change NDEBUG to _DEBUG in the Preprocessor Definitions.
Once that's done, your project should be able to compile, link and run. If not, you can test your paths in a console (Start-Run, type cmd, press enter), by for example typing echo %OSG_LIB_PATH% or dir %OSG_LIB_PATH%. With those commands you should be able to see what is wrong.
Important note about plugins
Once in a while, we get a message on the mailing list asking why the version number is added to the bin\osgPlugins directory name. Normally, the reason they ask is that after updating their copy of OSG, they had to modify their project files or their PATH to change the version number to point to the new directory.
There is never a need to add that directory to your library search paths or PATH environment variable. The OSG knows how to find the plugins by itself. In general, it will try to add osgPlugins-<version> to the directories in your PATH until it finds the right one. And since it knows its own version, it will find the right plugins directory.
If you had to add that directory to your PATH, for example in order to get examples to load the .osg files (cow.osg for example), that means that you didn't build the INSTALL target after compiling OSG. In that case, the plugins will reside in directories like ...\OpenSceneGraph\build\lib\osgPlugins-<version>\release. So the problem is not the version added to the directory name, it's the lib instead of bin, and the release subdirectory. That's because CMake builds DLLs in the lib tree, and then the INSTALL target copies them to the bin tree, more specifically to ...\OpenSceneGraph\bin\osgPlugins-<version>. And since ...\OpenSceneGraph\bin is on your PATH, OSG will find them fine.
More generally, you should never have to put a reference to a subdirectory of the build directory into your environment variables. That is just a temporary location where things get built. Once the INSTALL target is run, the files will be in their final locations, which are bin\ for application executables and DLLs, lib\ for libraries, include\ for headers, and share\OpenSceneGraph\bin\ for the example executables.