I think Unreal 5’s Landscape should support infinite maps, at least 100,000 square kilometers. When you have a heightmap of 100,000*100,000 pixels. The world partition detects that it is too large and can be automatically split into multiple Level asset files (the Landscape size in each single Level is set by the user), and the split level file automatically becomes the sub-level of the level. All levels become a whole, and in The world partition view, are completely integrated.
This solves three problems:
If you use The world partition function, then each Landscape is only 81618161 at most. If it is a world of 100100 square kilometers, you need to puzzle 10 maps, and deal with their connection problems, and when streaming between different Landscapes Problems that may arise.
If you continue to stream with UE4 levels, The world partition is meaningless, complex manual puzzles, and you need to consider the possible streaming problems between each Landscape.
All Landscapes are placed in one Level. When first created, the low-performance computer may not be able to withstand the power of creating large terrains, causing UE5 to crash.
100,000 sq km is approximately 320km x 320km (and 320,000 x 320,000 meters or pixels).
A 320,000 x 320,000 heightmap would be 205GB just for the PNG or RAW file.
What software will you use that allows for a heightmap of that size?
Even if you split this heightmap into 8129x8129 tiles, which are the largest supported, you would have 40x40 tiles or 1600 tiles to deal with. If you went with 1009x1009 tiles, you would have 318x318 tiles or 101,124 total tiles!
What software do you know that can split a 320,000 x 320,000 resolution file into 1600 or 101,124 tiles?
A Project is typically 10x larger than the heightmap size after importing, so the Project would be 2TB in size.
Now the big question becomes what computer system are you going to use to import all of these 1600 tiles with?
A 64km x 64km tile set requires a computer with 512GB of main memory and an RTX-8000 48GB video card to import the tiles or load all cells. I’ve done these tests on dozens of large worlds, so I know the numbers.
On my dev computer, an R9-5950X, 128GB, RTX-3090, the largest world that I can import before running out of memory and UE5 displaying an error and exiting during importing is 44km x 44km (2000sqkm).
So what computer will you use to import a 320km x 320km tile set??