/usr/include/Inventor/ is in inventor-dev 2.1.5-10-21.
This file is owned by root:root, with mode 0o755.
There are a lot of files here (509 total). We're only showing the immediate contents of /usr/include/Inventor.
/usr/include/Inventor
..
/usr/include/Inventor/Sb.h
/usr/include/Inventor/SbBasic.h
/usr/include/Inventor/SbBox.h
/usr/include/Inventor/SbColor.h
/usr/include/Inventor/SbDict.h
/usr/include/Inventor/SbLinear.h
/usr/include/Inventor/SbPList.h
/usr/include/Inventor/SbString.h
/usr/include/Inventor/SbTime.h
/usr/include/Inventor/SbViewportRegion.h
/usr/include/Inventor/So.h
/usr/include/Inventor/SoDB.h
/usr/include/Inventor/SoInput.h
/usr/include/Inventor/SoInteraction.h
/usr/include/Inventor/SoLists.h
/usr/include/Inventor/SoNodeKitPath.h
/usr/include/Inventor/SoOffscreenRenderer.h
/usr/include/Inventor/SoOutput.h
/usr/include/Inventor/SoPath.h
/usr/include/Inventor/SoPickedPoint.h
/usr/include/Inventor/SoPrimitiveVertex.h
/usr/include/Inventor/SoSceneManager.h
/usr/include/Inventor/SoType.h
/usr/include/Inventor/Xt/
/usr/include/Inventor/actions/
/usr/include/Inventor/bundles/
/usr/include/Inventor/caches/
/usr/include/Inventor/details/
/usr/include/Inventor/draggers/
/usr/include/Inventor/elements/
/usr/include/Inventor/engines/
/usr/include/Inventor/errors/
/usr/include/Inventor/events/
/usr/include/Inventor/fields/
/usr/include/Inventor/manips/
/usr/include/Inventor/misc/
/usr/include/Inventor/nodekits/
/usr/include/Inventor/nodes/
/usr/include/Inventor/projectors/
/usr/include/Inventor/sensors/