Use Async Loading Screen from UE marketplace Async Loading Screen in Code Plugins - UE Marketplace. Also, it received Epic mega grant. Without that you have 2 options:
- use media player with material on user interface to get play video at UMG. But it is freeze.
- all maps-levels must open by streaming
Your level structure:
Splash.umap (Persistent)
GameLevel1.umap (Persistent)
GameLevel1_001.umap (Sub-level of GameLevel1)
GameLevel1 should have almost nothing in it. It’s basically just a container for your sub-levels and only holds the loading logic. The sub-level(s) should have the actual game content.
- Open Level on GameLevel1, but because it has nothing in it, it should be almost instant. Now, GameLevel1 is new persistent level and it destroy all stuff(UMG loading screen, also) and display itself
- On the Begin Play of GameLevel1, re-create your loading screen. It is done in 1 frame, you will not notice that its being destroyed and re-created
- Use Load Stream Level to stream in GameLevel1_001