# Updating very old add ons for use in Blender 2.8-2.9 onwards

I have a question regarding a very old add on for Blender, that I am hoping to make work in the current version.

Currently, I have gotten into to developing add ons for the Space Simulation software Celestia. In order to for Celestia to use an add on, one of two 3d file formats must be used. .3ds or .cmod, are the two file formats that the software currently supports. However, a majority of the add on creators for Celestia use Windows only programs such as Anim8tor, which have the ability to export .cmod files to Celestia. As I am on a Mac running 10.14.6 Mojave, I’am unable to use such a program.

With that being said however, I did learn that very early on, there was in fact a .cmod export add on for Blender. Unfortunately, the add on is so old, that not even 2.79 is capable of running it. Therefore, my question is is it possible to modify this add, on in order to make it work correctly with a modern version of Blender? If so, what will I need to do in order for the add on to be compatible with the most recent versions of Blender?

If you are wondering about the .cmod file, there is lots of information about it here:

https://www.classe.cornell.edu/~seb/celestia/cmod_format.html

In addition, I have also included the link to the .py file that I am referring to as well:

https://celestia.space/forum/viewtopic.php?f=2&t=9957

Thanks!

• First - import bpy. Second - it's only 70 lines, and most of them are self-explanatory. – Klafciarz Feb 6 at 2:05
• The 3ds exporter is up to date. Addons with import Blender are written for version < 2.50 – batFINGER Feb 6 at 6:27