The blue area (which is filled with a blue texture) has been added to this terrain using a flow map. To be able to add water to that part or make the blue texture move and simulate water movement, what can be done?
A part of the flow map:
Landscape material:
You probably can make shader, however you need some meshes manually placed in all those streams.
Niagara cannot handle such big number of particle emmiters you would need to cover whole area.
With new fancy stuff in shaders departament, it is worth a try to see if you can make shader that is seamless on multiple scattered meshes and with 3d uv coordinates.
If so you could use landscape material and scatter boxes or low poly spheres along those streams, then make shader that makes water surface out of them.
However nothing will beat manual labor and placing/creating all those streams manually
Do you know how it is possible to export those streams or flow maps as a 3D mesh from World Machine?
No idea, i use gaia. Well kind of not use that much. For games such generated landscape at best can be used as base or mockup.
Also such generated meshes would be huge, and unreal does not like meshes that have big dimensions (Well maybe that changed with nanite)
So if you are making game, you do not need water everywhere (instead use landscape as rough mockup and ■■■■ out tiny are first)
If you are making some movie or something else and you do not care about performance, you should also focus on areas that are important.
In open-world games where there are, for example, 100 missions for people to play, do developers of those games design the missions while the terrain is already open in the game engine? Or is there any way to create missions without loading the terrain in the Unreal Engine since the terrain slows down the game engine?
I am just pointing out that you are starting from wrong end of making game.
Yes use such landscape, but at beginning more as reference to “final” map size and terrain shape. Do not bother with water and streams on grand scale.
Use that landscape as background, make it look TOLERABLE (that is enough for now) instead focus on developing your style. For that make tiny 1 section of map, something like house with few trees and things. Polish that tiny map first.
Then start coding and using that tiny place to test all systems.
Grand scale map (like you doing now) should come almost last in dev cycle. When you have quest system, know art style, have finalized movement and fighting, all that.
Imagine you made whole map (like you starting now) all with details and water and stuff, then you decide speed of your character is too high, you rather have him walking not running. Now whole map needs to be sized down so player is not wasting 10min for walking from village to village.
So if you are making game not some render or demo, focus on tiny map first (keep landscape just as background), then focus on gameplay.
Ps.
If you are serious about being SOLO indie dev, focus on what is outside of your comfort zone. Ie. do not stick to level design because you know it best, do things that you do not know and are easy enough to learn fast.
What you posted is absolutely not a flow map. Look up what flowmaps are…
