Single Layer Water Specular Reflections not blocked by Volumetric Clouds in 4.26

Development World Creation
1

I’ve run into a really annoying issue with this shader that I can’t seem to find a fix or workaround for.

Specular reflections rendered from a directional light used as a sun will not be blocked by volumetric clouds. This also happens with other translucent materials. Specular reflections do get blocked with default lit shading.

Here is an example of what is happening, and how clearly wrong it is:

SingleLayerWater
SingleLayerWater3610×1000 447 KB

And here you can see the Sun’s specular highlight correctly blocked by the clouds on a default lit shader:

OpaqueWater
OpaqueWater3610×1000 413 KB

This example is using Ultra Dynamic Sky, but I couldn’t find anything that could be causing this issue.

Is there any way to get this to work?

2

After looking into it further, cloud shadows are not being cast on these surfaces either, so it isn’t just the specular highlight.

Also, I tested this in 4.27, and shadows do appear, but the specular highlight is still not shadowed.

3

Any fix for this? My sunlight is passing through objects and reflecting on the water surface. This only happens on the water surface

4

Currently having the same issue on 4.26

Volumetric Clouds are casting shadows onto a Plane with the Single-layer Water shader. These cloud shadows are not occluding the sun’s reflection for some reason.
Tested using a Default Lit shader on the same Plane, and the cloud shadows occlude the sun’s reflection.

*also used a basic cube to cast shadows onto the Plane (with Single-layer water) and it does occlude the sun.

Is this a bug with the interaction between Single-layer Water shader & Vol Cloud?

5

in your water material enable screen space reflections, this always solved it for me.

6

I’d suggest disabling default reflections alltogethere and outputting a cube map as the reflection into the material manually.
It lets you select exactly what you want to capture and allows for setting up some more dynamic low scalability options;

Are you running this game on a potatoe?
Yes > ok, we will disable reflections all togeter.
Sort of > well, what elements do you want reflected in the water? Sun, clouds, landscape, trees, grass, whatver other option you feel like adding).
No, its top of the line > ok, all settings are on, with ray trace. Enjoy your 2fps :stuck_out_tongue:

The engine essentially does something similar with reflections, but you do not have control over it unless you modify the engine source.

The engine has tons of issues if you make a localized moving reflection capture manage the reflections.

Lastly:
Screen space means that only what is on the screen is being taken into account (dha?).

As such, you often see a vignetting effct that may be a deal breaker on a water surface. Objects on the screen’s edge are not exactly (if ever) entierly on screen.

And the setting will not change light bounce in a bake, which removing reflections in lieu of your own map would possibly prevent.