Diagrams about the engine

Godot Version

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Question

Hello! It’s my first time posting here, so I’m not sure if it’s the right place.

I’m doing a college project and I chose GODOT Engine for it. I’m interested in contributing in the future and I’m using this work as a bit of motivation to start joining the project.

Let’s go:
I need to make 3 C4 diagrams: the system context diagram, the container diagram and one of the student’s choice. I’ve already done the system context and container ones and I think they’re ok, the problem is the third one.
I wanted to try to make a concurrency diagram using a sequence diagram as a base, but I’m overwhelmed by the number of classes to try to understand the relationships and how the threads work in them.

I would like to try to understand this: where do I start? where should I go?

I imagine that making a diagram like this for the entire system is impossible for me now, so I would like to understand a smaller part, for example: how do threads work when trying to render the scene?

Thank you, best regards!