Hi Sebastian, I just did a build of OSG 3.2.1-rc2 with install and a run
of cmake on OSS that seems to work, this is all on a x86 target with
visual studio 2012 and cmake 2.8.12.2
osg sits in S:\tools\OpenSceneGraph\3.2.1-VS2012\
build directory S:\tools\OpenSceneGraph\3.2.1-VS2012\build
install directory S:\tools\OpenSceneGraph\3.2.1-VS2012\install
OSG_ROOT set to S:\tools\OpenSceneGraph\3.2.1-VS2012\install as an environment variable (System)
cmake on OSG, i am using downloaded third party depencies
built Release in visual studio (it seems that if release is not built the findOpenSceneGraph does not work)
ran "Install" in visual studio
the Install folder will contain 'bin', 'include' and 'lib' with appropriate entries, .dll in bin, and .lib in 'lib'
ran cmake in OSS that ran successfully and found the correct OSG version
I also attached my Version file, I hope this helps.
I read your error message again, I have to admit that I saw a different error