Conversion of 3D objects (.obj) to MultiGen Open Flight models (.flt) seems to be doable and possible with programs like Blender or similar 3D modeling tools. Unfortunately, we couldn't find anything specific regarding this conversion except for fact that Blender should support it.
Convert 3D object graphics to MultiGen Open FLighT file.
We have found 3 software records in our database eligible for .obj to .flt file format conversion.
Microsoft Windows software - convert obj to flt on Windows
A very popular free program used for work with 3D graphics
Convert from obj file format
The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned obj to flt. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.
Apple macOS / Mac OS X software - convert obj to flt on OS X
The Mac version of popular free 3D graphics software
Linux/Unix software - convert obj to flt on Linux
Easy-to-use 3D modeling utility