There are many 3d modeling formats around, some hold information about polygons, and some point clouds. Some formats are open, some are propriety.
When it comes to data from radar for object tracking purposes, point cloud formats are the appropriate subset of the available 3D modeling formats to use.
The two main categories point cloud files are ASCII and binary. ASCII formats include XYZ, PCD*, OBJ, PTX and ASC. Common binary formats include FLS, PCD, and LAS. And some are capable of both ASCII and binary formats.
With ASCII files, each line of text represents a single point (x, y, z). The main benefit of ASCII files is that they are usually well supported, can be edited with a regular text editor, and do not require specialist propriety software.
RadarIQ provide a sample application for capturing point cloud data in XYZ, PCD, PLY, LAS or Octomap formats. These formats are non-propriety and can be easily opened with a wide range of software, or converted to other formats if required. The RadarIQ sample application for point cloud capture will be available in the RadarIQ GitHub repository.
* PCD format specification: http://pointclouds.org/documentation/tutorials/pcd_file_format.php