Detailed blog post: https://thegabmeister.com/p/portals-level-streaming/
Taking inspiration from Ratchet & Clank: Rift Apart, I experimented with a portal transition effect between maps using level streaming in Unreal Engine. I used Epic’s Infiltrator Demo and Zen Garden for the 3D environment assets. Other assets I used are listed in the blog post. Featured in 80 Level: https://80.lv/articles/recreating-ratchet-clank-portals-in-unreal-with-level-streaming/
Portal Transition Effect