I’ve been trying to get a character to interact with the Water System using Fluid Sim, but haven’t had any success, even after watching multiple YouTube videos. Even the Fluidsim_Terrain demo map that’s included with Engine > Plugins > Water Content > FluidSimulation isn’t working correctly. Apparently, there’s a bug with the M_Fluid_Sim_01 material where it’s missing FoamRT. But even after adding that in, it’s still not working.
When I open, Engine > Plugins > Water Content > FluidSimulation > WaveFoam > WaveFoamRender, I get numbers in the Viewport. Could this be the issue?
Any tips, suggestions, or settings that I should be aware of to get the Fluid Sim working correctly would be greatly appreciate. Thanks in advance!
This may not help much, but I have had the same issue. I found out that the fluid sim in 5 or 5.1 only works when it is at z-level 0. So, currently the only work around is having all water systems at z-level 0, which isn’t feasible haha. I am going to dive into where the math is being done for this and try and an offset value param for where the landscape is compared to level zero. Hopefully this helps a bit
Thanks for the additional info! I’ll look into that to see if that fixes the issue.
I was trying to use the Niagara Fluid System since the Water System / Fluid Sim seemed broken, but apparently (and correct me if I’m wrong), the Niagara Fluid System is a lot more expensive.
From what I have heard, Niagara CAN be more expensive, but It depends on how many particles you are spawning when you make your systems with it… if I am correct haha. Don’t quote me… I am still working through reading all the Water System code and blueprints to figure out what is causing the system to only work at Z-index 0. It doesn’t make much sense logically. The issue sounds like somewhere in the code it reads the z-index of the fluid sim and compares it to the z-index of the water, or the water depth, to create the necessary splash and ripple effects at the proper height based on those parameters. However, I have not located this yet haha
Just going by logic:
The system has to use render targets.
Render targets are likely bugged or broken.
Theres a few reasons why, but they messed with the rendering pipeline a lot. Its possible they disabled something that the RT relied on like writing to the alpha channel or similar.
Either way, like for everything, you should make your own system so you know how it works and how to fix it…
I faced the same problems using UE5.3.1, after a day of investigations I found a possible fix
Made a small video how to fix it, hope it will help someone
This video is great, now I can get ripples without Z=0.
But it may not work if Terrain Mode is Terrain Water Depth Only or Terrain with Elevation.
Does anyone know anything about this?
Hello!
I made a video with a temporary fix for interactive water, basically I attach that sim fluid to the character which solves the problem with different z in case you have several rivers or lakes with different z.
Personally, I have a problem with a large map that uses World Partition, for example the water interacts in the area where the character spawns but then if I load another cell and go back to the first cell the water is no longer interactive, I couldn’t get figure out what the cause is.
