Raytracing reflections in water?

Development Rendering
1

Hello again,

I am experimenting with water surfaces with raytracing in UE4 4.22.3.
It seems like raytracing reflections don’t work on surfaces with translucent blendmode. The documentation says, it should: Link

My material looks like this:

rt_mat.jpg
rt_mat.jpg1706×1004 252 KB

And the result is this:
rt_screen.jpg
rt_screen.jpg1067×522 117 KB

As you can see, the rock is not being reflected.
Raytracing does work generally, as you can see here. Only with translucent blendmode, it doesn’t.
rt_opaque.jpg
rt_opaque.jpg1069×518 90.5 KB

I have some more issues regarding refraction index and SSR. But they don’t fit this topic.
Therefore I just ask: Is there a good raytracing water material or tutorial available anywhere? I couldn’t find anything interesting.

Regards
Christian

2

Hm, are you sure that raytracing is on? Show me your postprocess settings on Raytraced Reflection tab, how many bounces do you have there, normally you should go over 1 to get some good results?

3

Hi, I am not on my computer at this moment.
But I can asure you, that raytracing is on. The reflection in the lower image looks blurry because I raised roughness in the material to make it look better.
I can crank the bounces up but that shouldn’t show any effect as the water is the only reflective surface here.

In case my babbling was confusing: The problematic image is that one in the middle. Where there is no reflection at all except some ugly SSR.

PS: Now, I am back home.
Attached you find the desired screenshot.

rt_pp.jpg
rt_pp.jpg1477×1019 313 KB

4

In your post process settings, translucency is set to raster but should be ray tracing.

5

Yeah, thank you. Found it.
Now there is a new problem :wink:
The depth fade node, which is important to simulate material depth, seems to not work for raytracing.
I can’t think of an alternative, an additional volume material seems too expensive, I didn’t even try it out.

Are there any suggestions?
Kind reagrds
Christian