I just uploaded a first test-version of the new Blender2P3D/FSX toolset. You can find it in the Resources, currently listed under Scenery/Tools - but I'd like to stress that it works for aircraft, too.
Here's the Link:
Blender2P3D/FSX is an addon for the latest version of Blender: 2.8x. It is a continuation of the work performed by various members of the fsdeveloper community to bring you Blender2FSX. This new toolset features a new UI, incorporation of...
I started writing a wiki entry for this tool to explain some of it's part better. Many things are the same as in the original Blender2FSX tool, but there are also some major changes to how certain things are done, so please stay tuned for more information!
This is considered a test-build, so please make sure to make backups of your original scenes before starting to use this toolset - I make no guarantees for your files if you use the addon.
All elements of the addon should be functional, but I don't have the capacity to test everything. In particular, anything to do with scenery creation is outside of my scope, so please let me know if something doesn't work for you, or if some important feature is missing so we can work together to fill the gaps.
Please note that you will have to re-assign all your texture maps when changing the P3D/FSX material mode to specular or PBR! I haven't found a way to retain that information while switching the material nodes around. If you're importing an older project, make sure to switch the material mode at least once for EVERY material to ensure that the shader graph nodes are set up correctly. Afterwards, you can modify the shader to your liking - as long as you don't change the main node (either BSDF Principled or Eevee Specular), the exporter should pick up the right textures.
When switching materials, the addon will replace the shader graph and set it up in a way that represents the shader of P3D/FSX. That means you can use a FSX normal map (with red/alpha swapped, green inverted, etc) and it will show up - more or less - how it shows up in FSX. The only exception to this is that the texture shouldn't be flipped vertically!
The exporter will setup different templates in the .X-file, depending on what SDK you're using. If you want to export to PBR, make sure that you initialized the P3D v4.x SDK. The exporter currently doesn't give back any feedback on the UI of Blender. If you want to make sure that it's doing what it's suppose to be doing, open the Blender console before exporting your scene.
I think those are the main issues for now, let me know what you think and if it works for you. We have a few more items on the to-do-list that hopefully will be integrated as we move forward and I'll be listening to what you're saying and do my best to accommodate your suggestions.