Possibly because of ffmpeg and cmake updates, openscenegraph doesn’t compile any more. FindPackage-functionality that cmake uses doesn’t work, and there are various ld linking errors.
There are some workarounds to get it compile, but seems like the end result has serious performance issues.
I have reported the issue at OSG github: Compilation and performance issues on Linux Manjaro · Issue #1191 · openscenegraph/OpenSceneGraph · GitHub
Affected packages: openscenegraph, and various related AUR-packages, e.g. AUR (en) - openscenegraph-openmw-git . To note, the prebuilt openscenegraph package fails at least with OpenMW development version 0.48 (error is about some package not found or not linked properly).