I know this is not an easy question:

 

How can I render the game a second time from bird's-eye view as a minimap and then display the rendered scene on the screen as a minimap?

 

You don't have to tell me how to render it, but it would be really helpful if you could tell me where I can find the place where the game is drawn in the code.

 

Thanks in advance!

Try looking at how a Minecraft map draws from birds eye view.

I assume it starts from the top of the sky, and keeps going down until it hits a block. Do this for each block around the player. I am not sure about the color for each block though

Do tell - you want to create terrain+entity "map" (like vanilla one) or real full-spectrum rendering?

Rendering from a given point is easy (this is assuming you mean in the "if the player was there" with perspective, shaders, and all that).

 

There's a handful of things to keep in mind (graphics settings*), but essentially you wait for a (pre or post, pick one) render tick event, then relocate the camera (you will need an entity to target), render, then switch everything back.

 

You render to a dynamic texture, then do whateverthefuck you want with it.

 

*You might want to disable particles, clouds, or other things.  Save the current value, render, then set the values back, just like the camera.

Thanks for your answers! I think I found the place where the world is rendered.