[1.11] IModel questions

Hi,

I'm trying to figure out how the IModels work, because I want to import multiple models from JSON files and render them at one time.

I've a few questions:

1. What is the difference between IModelCustomData and IModel?

If I look at the interface, it has another method called 'process'. When reading the documentation above it, I still don't get it.

2. What does getDependencies?

3.  What is TRSRTransformation.identity();

4. The method bake(IModelState state, VertexFormat format, Function<ResourceLocation, TextureAtlasSprite> bakedTextureGetter):

- What does the VertextFormat parameter do and how do I use it?

- What does the bakedTextureGetter parameter do and how do I use this?