How do I make my own loading screens when changing maps in doom 3 map editor?

[Raven91]

How do I make my own loading screens when changing maps in doom 3 map editor like, this? 

https://www.google.se/search?q=doom+3+map+loading&hl=sv&source=lnms&tbm=isch&sa=X&ved=2ahUKEwiYssrDhcb4AhUWs6QKHXxuACkQ_AUoAXoECAEQAw&biw=1648&bih=606&dpr=2#imgrc=ywhkPK4vazFrKM

Edited June 24, 2022 by Raven91

[Tetzlaff]

This is realised through a gui file. I don't have Doom 3 installed at the moment, but you could download a custom D3 level and see how it's done.

[Arl]

Indeed, each map has a homonym .gui in guis/map folder. The text and image of such map is defined in there, and then the engine loads that .gui which is named alike as its loading screen.