Immersive Portals is a decorative mod that makes Nether portals more realistic and beautiful. Now you will see through it another dimension and pass into it instantly, like through a door. Accordingly, from Nether, the ordinary world will be visible at the point where the portal stands. The only drawback of the mod is the increased load on the computer, for those who do not have a good supply of FPS, it is better not to use it. There is also Immersive Portals for Forge.