How to integrate .ply file from cartographer to octomap_mapping

Hi, I have point cloud in .ply format from Cartographer and I want to use this for generating the Octomap in Rviz using this octomap_mapping. Is it possible to do so or do I have to use separate viewer for generating octomap or writing a separate node to read the .ply file and then publish as pointcloud2 type can also be an option?