I definitely need to add this to the main thread later on, but the main thing is is to add a single or multiple LOD lines to the XML file (that corresponds with existing LODS), and then do the submodel merging itself by adding the “MergeModel” syntax with your mesh livery GLTF file.
For this ATR example, you can just copy and paste the XML file from the model folder of one of the official liveries for the ATR itself.
Here’s an example for the ATR mesh livery I’m working on:
NOTE: Make sure that you rename the (or each) MergeModel syntax to the mesh livery GLTF file you’ve just compiled earlier.
After merging the model in the XML file, make sure that the model.CFG text file is also present, and with the “normal” line referencing the XML you’ve just edited in the same folder.
After all is said and done, all you need to do is to re-run the MSFS layout generator of your choosing on your livery addon folder as usual.
Really sorry that I’ve just gotten into this, I’ve been quite busy with lots of stuff, including several livery projects and personal projects of mine.