plugins	Link	effect
GeyserUtils	Github	Get your Geyser to support calling some BE stuff
GeyserModelEngine	Github	Make your bedrock support MEG4
GeyserModelEnginePackGenerator	Github	Help you automatically transform the model to generate resource packs

Put GeyserModelEngine in the plugins folder (only Spigot or forks of Spigot supported)
Put either geyserutils-spigot in your plugins folder aswell (geyserutils-velocity/geyserutils-bungeecord in your Velocity/Bungeecord plugins folder if you use it)
Put GeyserModelEnginePackGenerator and geyserutils-geyser into plugins/[Geyser-Folder]/extensions
Inside floodgate set send-floodgate-data to true in your Velocity/Bungeecord folder and copy over the key.pem into your backend floodgate folders

Start the server to generate the relevant configuration files, and then shut down the server to convert any models.

Convert Models

GeyserModelEnginePackGenerator is capable of generating models all by itself. After generating it will also apply this pack automatically.

Firstly, install packer plugin for your blockbench.
Then, open your bbmodel, go File -> Export -> Export GeyserModelEngine Model, you will get a zip, just unzip it to input folder.

Each model should have a separate model folder Subfolders are supported if you want to categorize them

Restart the server or reload geyser to start generating the resource pack.
Go to plugins/[Geyser-Folder]/extensions/geysermodelenginepackgenerator, and you should see your pack generated!

Tips

Pay attention! The pack only regenerates when the number of models changes, you can technically speaking remove the generated_pack folder to force a reload aswell.
You do not have to manually put the pack into the packs folder of Geyser, the extension is capable of loading the pack itself.
Choose a right texture when use the packer.