The 3MX format consists of 2 types of file: one master file in JSON format and a tree of sub-folder/sub-files in binary format. The single master file contains the scene metadata, and it is identified by the 3MX extension. The binary files contain the geometry, and are of type 3MXB (3MX binary). The 3MXB files typically describe one unique 3D textured pyramidal mesh.

Figure 3 shows an example of folder organization for a 3MX scene. The scene file is found in the root folder. The mesh description is split in multiple files, organized in a tree structure. Sub-folders represent subtrees of some intermediary node in the LOD structure described in the previous section.