Particles invisible with ray tracing

Hi there

I’m using cascade particles from an older project… originally created in 4.18. They look fine when I drop them into a map but once I turn on ray tracing under translucency in the PostProcessVolume they become invisible. I’m using a RTX 2080 card. Is there something I’m missing? Is there some trick to getting particles to work with ray tracing? Is there a magic switch I need to switch on or off? I’ve also tried the same translucent material on some Niagara particles, but it actually does the opposite, makes them solid and over blown looking and looks like its adding refraction even though the material doesn’t have any refraction. Any help in the matter would greatly be appreciated… pulling my hair out :frowning:

Thanks

Hi there,

As one sad developer to another, particle effects are simply not fully supported. And Cascade is unlikely to ever be, since it got replaced with Niagara. See the raytracing documentation at the bottom for a list of supported features.

https://docs.unrealengine.com/en-US/Engine/Rendering/RayTracing/index.html

Same problem here, ue4.253 . RTX translucency not working on translucent materials over sprites , you can still use opaque materials at some cases like small sparks or dirt , sprites do render on opaque.

And certainly you can turn translucent to be RASTER instead , and leave raytrace to reflections and AO, so your particles will render ok, but its like driving a Lambo on a parking lot , it doesn’t feel entirely good…

looking forward to a solution…

Hi, a little late but I was having the same problem. one solution I found is to set in the particle material blend mode to masked and shading model to default lit, and added an opacity mask to anything that needs to be opaque; that way ray trace won’t affect it as translucent. the results are not as pretty looking but it worked for me.

I found a solution that seems to work without problems. Change the Particle Material, Material Domain to Deferred Decal instead of Surface or whatever else you might have it as.

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Hi. Is there another solution for this? I need transparent particles and ray traced translucency at the same time and the Deferred Decal method crashes Unreal Editor every time. What a pain!