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Rough translucency + rtx

Hi guys, is it possible to create rough translucent material using raytracing? So that things behind it would look sharper the closer they are to the object and “blurrier” as they are further behind.

something like in this attachment

think milky frosted glass or plastic type of material. I saw some tutorials using spiral blur on raster objects but it kinda looked bad and I completely failed to get roughness to affect translucency (would only affect reflection) on material. Is it possible to build such a material so that it looks convincing?

I’m getting something using the singlelayerwater shading model+high frequency normal maps but it won’t display glass objects behind it

Is translucency sort priority set to higher for the milky glass, and lower for the glass behind it?

Tried it either way, I think the shading model (singlelayerwater) doesn’t allow this. Normal translucent works but looks worse. It’s kinda hard for me to work with glass objects in UE even with raytracing. Not sure what I’m doing wrong, tried automotive pack shaders but they also don’t look too good.

You are probably doing nothing wrong. UE raytracing and glass are two things, that until now don´t go well together, and frosted glass is even worse :frowning: There are some solutions, that rely on post effects (like blurring), but those usually fall apart the moment, you want see them in a mirror or any reflection. Cuz most post effects cannot be reflected with raytracing.
That´s one thing, where screen space reflection or planar is still superior. And thats probably the reason, why most demo scenes are with rocks, and not with water or ice/glass and clouds/fog, because then you would realize, that most post process stuff and particles cannot be reflected in raytracing ^.^ unless you make the particles real meshes/cpu particles (which are way more expensive).

I hope, they find an acceptable solution for this problem with UE5 (have no hopes for UE4.26 in that regard, although i wonder about their volumetric clouds and reflections in water, etc.).

Yeah I’m noticing that reflections and shadows are working mostly really well while translucency is pretty bad looking in some cases.

I’ve seen some experimental shaders on YouTube but nothing is currently available from those afaik…

Most of the methods I know of to get blurred glass have this limitation because they are reliant on using the scene color texture which doesn’t include translucent objects.

I believe this can probably be overcome by using a render target instead of scene color (essentially portal rendering but for glass), but that is more complicated to set up and not very performant.

None of this will allow you to control translucency through roughness, that is something you will need to set up yourself.