Hi,
For visualization, RTAB-Map depends on the
PCLVisualizer, which depends on
VTK. VTK uses OpenGL under the hood. Maybe VTK can be built with OpenGL-ES.
The Freenect option is disabled because RTAB-Map was not built with Freenect support (it is not detected by CMake). You may have "With Freenect = NO (libfreenect not found)" when executing CMake.
I don't know if it is possible to install ROS on the Odroid board, but you may have access to
RTAB-Map ROS, which has a
mapping node detached from the visualization stuff. Also, you would have access to some nice tools from ROS if you plan to make rtabmap running on a robot.
Otherwise, you may take a look at the
C++ RGB-D Mapping example, without using CloudViewer and Qt stuff.
Cheers