The FBX importer does not have an Axis Conversion option in the UI. Only exporters have this option exposed in the UI. This is because the 3ds Max FBX plug-in calculates and applies the Axis Conversion automatically upon import.
What does the automatic axis conversion do?
The importer looks at the up-axis used in the host application. In 3ds Max, this is always Z-up. It then compares this to the up-axis set in the incoming file. If both up-axes match, the importer applies no conversion. If they do not match, the importer applies a conversion to the imported data to match the host application’s up-axis automatically.
When the up-axes do not match, it creates in a longer import process, because the 3ds Max FBX plug-in must rotate each root object 90 degrees to match the host application up-axis. This is especially true of Maya or MotionBuilder to 3ds Max workflows.
The importer applies Axis Conversions only to root elements of the incoming scene. If you have animation on a root object that must be converted on import, these animation curves are resampled to apply the proper axis conversion. To avoid resampling of these animation curves, make sure to add a root node (dummy object) as a parent of the animated object in the source scene (source application) before you export to FBX.
