First of all, sorry. It is a long post containing weeks of research and struggle, but I promise worth reading, it’s a nice technical challenge!
I’d like to have an advice/suggestion/feedback regarding creating a Big Open World Landscape that is using both Landmass and Water plugin as well.
For a while I have been experimenting both on UE4.26 and on UE5EA as well. Nowadays mostly UE5EA.
As a start I created a big landscape 255x255 quads, 2x2 sections, 16x16 components, 8K over all resolution with total components of 256. (Also tried with 1x1 sections and 1024 components. For now let’s stick to the first version.) Layer edit was enabled, in UE5EA the world partition grid size was set to default 2.
Then I started placing Landmasses, Ocean, Rivers and Lakes. My issue can be reproduced also by placing just a single River of the Water Plugin.
Whenever I tried to move the River or it’s spline points I had a crazy FPS drop to 1~2FPS from 100~120FPS and the console kept saying timeout error messages that it is waiting for the GPU to catch up, eventually editor freezing up - yet no crash.
Now my GPU is GTX 1070 TI, but I also tried my little experiment on a friend’s PC who has one of those super expensive GPUs (namely RTX 3080), and there was not a millisecond of improvement. I had the very same issue on that GPU as well. We both have high end PCs with AMD Ryzen 3950X, 64GB RAM, SSD. Everything leads to the conclusion that it is a software and not a hardware issue.
I watched a lot of videos on youtube regarding the topic, and I came to the conclusion the issue is the number of components. More components on the landscape → more performance drawback. However I never had ANY in-game performance drawback regarding this, only editor performance drawbacks.
I am aware both UE5EA, and UE4.26 water and landmass are experimental, still I want to have this topic a bit more spotlight.
My goal is to have a big ocean, and a continent on that, the continent split by multiple rivers and lakes, landmasses, mountains and roads. (Yeah, I know sounds like a nice dream.)
Earlier I tried in UE4 the World Composition (which is deprecated and not recommended and will be replaced by World Partition), but World Composition does not support the Water Plugin either, and I would avoid using deprecated systems at this early stage of development.
I also have been experimenting on UE5EA with trying to unload the unnecessary grids, but the river was still unmovable due to freeze/FPS drop. I also tried putting the river in a different Data Layer called Water, still had the same issue.
I also experimented on the big landscape with standard sculpting tools, and I noticed whenever “Edit Landscape Layers” are enabled simple sculpting drops my FPS to 20~30 from 100~120. If the “Edit Landscape Layers” box is disabled, there are no FPS drops and it works fine. However, water and landmass requires edit landscape layers…
I also tried making multiple small landscapes on one level, that worked with Landmass, but not with Water plugin.
Since I’m in an early stage of the development I’d like to use the Epic’s factory provided plugins for my goals, but I’m not sure it’s the right choice.
Honestly at this stage I’m not even sure making such a big landscape is a good idea at all or not?
I am waiting your answers regarding how to have a “big ocean, and a continent on that, the continent split by multiple rivers and lakes, landmasses, mountains and roads” !
Thank you in advance!
UPDATE: I also tried to use a Landscape which was as big as the one above, but used less components (I used scaling like 200, 400, 800, even 1000.) The freeze issue disappeared, but the terrain quality was terrible, the rivers of the Water Plugin were discontinuous, so scaling the Landscape was not an option either.