Ray Traced Translucency displacement issue

I was having some trouble with the wind effect on some Quixel plant assets and whilst trying to figure out what the issue is I’ve found that Ray Traced translucency causes a doubling effect on some geometry using world displacement, even if the material doesn’t use translucency/masks. But if I set the translucency type to Raster in the PPVolume it goes away.


This shows the doubling effect is visible in the world but not in the blueprint preview (because that viewport isn’t using ray tracing?)

It’s also visible on other materials, the non-displaced original geometry is still visible under the surface of the object, its just not as noticeable as the displacement isn’t moving.

Is this an engine bug or is there something I can turn on/off to stop this from happening

What are the ray-traced settings in the PPV?

Here is a screen shot with the settings of the PPV visible.

When Ray Traced Translucency is on, there is a geometry doubling effect.

When it is set to Raster type for Translucency the issue stops. I should also mention that if the Max Refraction Rays is set to zero it also stops the issue, but it seems to be the same as disabling RT Translucency so that isn’t really a solution.

Can you post the asset as a downloadable? I want to check it in a project. There’s not enough information for me to see what else is affecting it.

Turn on this parameter in static mesh

Yes! This solves the issue, thank you very much

Any solution when using foliage?

thank you very much!! WORKED!

i have the same issue when using foilage…and no where to evaluate world position offset…

Hi Visuals. The solution I found for foliage in this case would be Modes > Foliage > Shift click to select all your foliage with the shadowing issue, and simply uncheck “cast dynamic shadows” will fix the issue.

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