Inside Unreal: Water System Deep Dive

We’re diving into the Water System for the first livestream of 2021! Join us this week to further uncover the seacrets of landscape limits, rebuilding the mesh at runtime, water material and blends, translucency, and wave setups at sea and shore.

Thursday, January 7 @ 2:00PM ET - Countdown


Sjoerd De Jong - Evangelist Lead - @Hourences
Victor Brodin - Community Manager - @victor1erp

Diving Into the Depths of Water as a Feature in Unreal Engine 4.26
Water System Documentation




Seacrets… lol


Can you dip into using water bodies to paint landscape materials? What blend type association for the paint layer, non-weighted?
And plug-in related settings in project settings :stuck_out_tongue:

Good stuff :smiley: I tried to get some results and got some but wasn’t satisfied coz it all looked a lot complicated… Many thanks team!!

Please upload the video to YouTube and see how to use water in projects created without using the Mass landscape plugin and the Landscape editing function. Most users want to add water to ready-made projects that they have created a long time ago and using standart brushes

Please, publish the project with working foam examples! Current one in Water Content folder has not foam on Play.

Can you please show us if the ocean mesh can they be resized to fit around a landscape that is 4096 in none of the documents or any tutorials that I’ve seen not 1 mention. I’m totally lost and my scene needs the ocean scene with great-looking realism

I would just like to know how to set the water system to work on a large landscape. 8k by 8k.
I simply can’t get it to work this way.

Go into “WaterMeshActor”, change “tilesize” to 4096, set “Far Distance Material” to “Water_FarMesh”. The defaults are a bit wonky atm it seems :slight_smile:

Go into the Water Material, make sure “ocean foam” is enabled, and set foam height bias to something between 0.6 to 1 (default is -1)

If you want to get experimental, put a BP_FluidSim_01 into the level, over the area you want (Check Show Water Mesh) to see its placement,

  • Use "Simulation World Size to control its Size, and “Wave World Size” to control the area of which is simulated.
  • Uncheck “Follow Actor” to make sure it stays in place while you test
  • Remember you only see results while you run “Play Simulate” for some stuff.
  • Uncheck “Use Custom distance field” in the water material. It’s only used when you use scene capture (I think), and you won’t get any waves.
  • Uncheck “Generate Distance field” in BP Fluid sim for same reasons. And uncheck “Use Scene Capture” in the Shallow water component"

Check “Simulate Wave foam” to get wave foam, though, you might want to turn down height bias so it’s visible. It’s finicky though because you need to play with “Resolution” (Size of droplets afaik), “Wave foam resolution” (quality of foam), “Damping” - how much water is restricting to going back to normal state, ie how stable it is. There’s also some settings only on the components to fluid sim, the shallow water and wave foam components.

For instance, you can set some “advect materials” on the shallow water component that controls how much water is “added” on forces etc.

There are also differences between Shallow Water and Ripple solver, with Shallow water being the more “sexy”, but also more unstable. some simulations only seem stable if you chose Terrain Mode - “Constant Water Depth”, for getting forces, etc. to work it seems to work to lower the resolution to “512”.

Foam, I think is generated by a color channel in the materials, but I haven’t managed to get any shore foam going, even though the Niagara shore “bouncing balls” works. One reason why we haven’t’ seen so much cool foam stuff in the samples is probably that they’re still working on the Niagara components.

There are some amazing possibilities by being able to access the WaterDistanceField and things in the Materials through the “WaterBodyData” node, there’s also a bunch of cool render targets for things like flow maps, water velocity, height, etc

But yeah, really tricky to juggle all the different numbers in the water body, materials, effect materials, resolutions, forces etc. I reckon they will make this more user-friendly over time. Wouldn’t be too hard to build something like the “SunSky” actor that packages everything nicely


Please tell us how to get water working for streaming levels. it wont render when using multiple terrain tiles loaded.


Thank you for the first part - I been able to see foam texture at least, but with BP_FluidSim_01 I have a problem - it’s just not working at all( I enabled Show Sim Area and Show Water Mesh and placed camera at the actor position, but nothing I saw, let’s wait for stream, maybe it will help.

I’m using world composition and water doesn’t show up at all.

Thanks for showing the new watersystem in depth today.

Would it be possible to explain the “WATER BODY EXCLUSION VOLUME”?

I got some problems making it work, in the detailspanel i cannot select the waterbody in the list.


Hello, I installed shallow and water plugins in 4,26, nevertheless I’m not seeing content and BP_FluidSim_01 nodes, how can I fix it?

Shallow Water Plugin is old and has nothing to do with the new system, If you go to the “Engine Content” Folder in your content browser, scroll down to “Water Content” and search for it there it should be there if you’ve installed the plugin :slight_smile:

‘Deep Dive into the Water’ system - wow that title seems so relevant lol :cool:

** also STICKY ** :rolleyes:

The trick to get the water working with my existing landscape was such a life saver!

Great this will be surprising

Thank you very much…

As feedback I think that the livestream could be improved by sharing file project : it’s very tricky - at least for me - follow the entire project modified. It would be much more usefull having the code in front og me and watch again the stream: in that way I could learn much more.

Except this, thank you very much for the livestream.