Hello.
I created a program in C++ using the FBX SDK 2020.2 . This program imports an FBX file, removes some objects, and finally exports the created scene as an OBJ file. When I remove all the materials present in the scene, the export of the file to OBJ occurs in a reasonable time, but when I don't perform this removal, the export time increases considerably.
The following table illustrates two conversions of an FBX file using the same program described above. The input file has a size of 1.5 GB:
| Mode | Import Time | Export Time |
| Materials removed | 00:11:19 | 00:04:21 |
| Materials not removed | 00:11:40 | 01:11:01 |
I don't understand the reason for such a significant change in export time. Perhaps the process of creating the .mtl file (which accompanies the OBJ file and stores information about the materials) becomes costly, as it is necessary to traverse the entire object tree of the FBX file in search of materials for each object.
Could someone tell me if this theory is correct or not? Is it possible to work around this problem and make the export process more efficient?
