Shallow water plugin not working in 5.8

Development World Creation
,
1

In 5.8 shallow water plugin doesn’t capture any depth information resulting in no simulation running when “use capture” is on. With “use capture” off, the simulation results in a rectangle which ignores the underlying landscape. Confirmed on a clean project with the open world level template. Is there any workaround? @DevonPenney do you happen to have any information?

2

Hey! I have the same issue; have you fixed it?

3

Nope - shallow water is completely broken.

4

The problem was in Niagara’s scene-depth sampling shader. Incorrect ground heights saturated at 65504, leaving water depth and velocity at zero.

In:

Engine/Plugins/FX/Niagara/Shaders/Private/NiagaraDataInterfaceSceneCapture2DTemplate.ush

Inside TextureProjectDepth_{ParameterName}, replace:

OutCaptureDepth = OutInBounds
    ? {ParameterName}_Texture.SampleLevel(
        {ParameterName}_TextureSampler, UVW.xy, MipLevel).r
    : DefaultDepth;

With:

[branch]
if (OutInBounds)
{
    OutCaptureDepth = {ParameterName}_Texture.SampleLevel(
        {ParameterName}_TextureSampler, UVW.xy, MipLevel).r;
}
else
{
    OutCaptureDepth = DefaultDepth;
}

Restart the editor, open Grid2D_SW_River, and choose Compile → Full Rebuild. Then test Reset with the viewport in realtime.

Keeping the sample inside an explicit branch restored valid ground heights and changing water depth/velocity. Reverting to the original shader reproduced the failure.

Verified on UE 5.8.2, RTX 5090, driver 610.88.

5

Hi all- I’m going to look into this real soon.

6

Does anyone have a log I can see for this problem? That might be helpful. Also, for those reporting it not working, what kind of gpu do you have?

7

This fixed for me… Thanks

8

Hi, my GPU is 5090 with all the latest drivers. I can provide you with all the info you need - I was debugging this issue for far too long and came to the conclusion, backed by experimental evidence, that the depth sampling in Niagara is just completely broken ATM. I didn’t check @AirborneCoder proposed fix so can’t confirm it works.