Have you tried comparing your setup to the Water Examples that was released by Epic? This can be downloaded via the Learn Tab on the Launcher if you’re not aware of it.
Using exponential height fog and atmospheric fog work with that that I can see.
Try comparing the setups between the two and let us know if you’re still having trouble.
I just tried reproducing this using the same example content but I see the translucency vertex fog working as expected.
I made a new level and placed the BP and then placed both atmospheric and exponential fog separately and both worked. You can see its vertex based by the vertex interpolation issue in this image:
I can only suggest making a new test level and placing only the water BP and fog first. Then verify the vertex fog setting is correct. Then possibly try placing a regular mesh without using the BP if that still doesn’t work.
Sorry for the necro… but it looks like it was never answered and searching still brings this post up.
I found something that worked well. In your Translucent Material, under the Translucency settings, be sure that Apply Fogging and Compute Fog Per Pixel are both ticked true. I did see a mild FPS hit when I did this, but it wasn’t so much as to make a huge difference. I hope this helps.
Also sorry for the necro, but I have the same problem with the Water Materials. I added the SM_Water_Plane mesh and it look ok, but the exponential heigh fog doesn’t work on it.
I tried the solution above and ticked Compute Fog Per Pixel, and it just messed up the whole material.
I’m getting similar issues…translucency isn’t getting fog details…dont know why…but when lumen-raster enabled in translucency it disappears but the reflections aren’t that good has ray traced