/usr/include/mrpt/opengl/ is in libmrpt-dev 1:1.5.5-1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/mrpt/opengl/include/
/usr/include/mrpt/opengl/include/mrpt/
/usr/include/mrpt/opengl/include/mrpt/opengl/
/usr/include/mrpt/opengl/include/mrpt/opengl.h
/usr/include/mrpt/opengl/include/mrpt/opengl/C3DSScene.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CArrow.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CAssimpModel.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CAxis.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CBox.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CCamera.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CColorBar.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CCylinder.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CDisk.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CEllipsoid.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CEllipsoidInverseDepth2D.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CEllipsoidInverseDepth3D.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CEllipsoidRangeBearing2D.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CFBORender.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CFrustum.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CGeneralizedCylinder.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CGeneralizedEllipsoidTemplate.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CGridPlaneXY.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CGridPlaneXZ.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CLight.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CMesh.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CMesh3D.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CMeshFast.h
/usr/include/mrpt/opengl/include/mrpt/opengl/COctoMapVoxels.h
/usr/include/mrpt/opengl/include/mrpt/opengl/COctreePointRenderer.h
/usr/include/mrpt/opengl/include/mrpt/opengl/COpenGLScene.h
/usr/include/mrpt/opengl/include/mrpt/opengl/COpenGLStandardObject.h
/usr/include/mrpt/opengl/include/mrpt/opengl/COpenGLViewport.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CPointCloud.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CPointCloudColoured.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CPolyhedron.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CRenderizable.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CRenderizableDisplayList.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CSetOfLines.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CSetOfObjects.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CSetOfTexturedTriangles.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CSetOfTriangles.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CSimpleLine.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CSphere.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CText.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CText3D.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CTextMessageCapable.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CTexturedObject.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CTexturedPlane.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CVectorField2D.h
/usr/include/mrpt/opengl/include/mrpt/opengl/CVectorField3D.h
/usr/include/mrpt/opengl/include/mrpt/opengl/gl_utils.h
/usr/include/mrpt/opengl/include/mrpt/opengl/graph_tools.h
/usr/include/mrpt/opengl/include/mrpt/opengl/graph_tools_impl.h
/usr/include/mrpt/opengl/include/mrpt/opengl/link_pragmas.h
/usr/include/mrpt/opengl/include/mrpt/opengl/opengl_fonts.h
/usr/include/mrpt/opengl/include/mrpt/opengl/opengl_frwds.h
/usr/include/mrpt/opengl/include/mrpt/opengl/pose_pdfs.h
/usr/include/mrpt/opengl/include/mrpt/opengl/stock_objects.h
/usr/include/mrpt/opengl/include/otherlibs/
/usr/include/mrpt/opengl/include/otherlibs/freeglut/
/usr/include/mrpt/opengl/include/otherlibs/freeglut/GL/
/usr/include/mrpt/opengl/include/otherlibs/freeglut/GL/freeglut.h
/usr/include/mrpt/opengl/include/otherlibs/freeglut/GL/freeglut_ext.h
/usr/include/mrpt/opengl/include/otherlibs/freeglut/GL/freeglut_std.h
/usr/include/mrpt/opengl/include/otherlibs/freeglut/GL/glut.h