A neoforge port of the Immersive Portal mod which is a port of the original Immersive Portals. The 1.21.1 version will be a backport once released.

NeoPortals is a mod that allows you to see directly through the portals, and walk between dimensions without a loading screen. Currently mod compatibility is mostly untested, but after the 1.21.1 backport I plan on pushing for additional mod compatibiltiy.

Original: /mod/immersive-portals-neoforge