Once the library is added as a submodule, you can include it in your project's cmake like this (replace LIBRARIES_PATH): OpenVDB has several versions, which means that maybe not all of your vdb files ...
SLAM-VDB is an open-source, high-performance 2D/3D SLAM system, built on the Robot Operating System (ROS) with OpenVDB as the map storage backend, designed for efficient map management and real-time ...