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Ray Traced Translucency disappear when hit play

Hello all,
I can’t figure out when I hit play, translucent surfaces are not displayed anymore?
I tested a simple sphere, with default settings except translucency setting froced to RT in PPV.

Am I missing something?
Thanks,

Can you give us a screenshot of the material you are using?
Also make sure the item isn’t hidden in game for whatever reason.
Rebuild geometry, rebuild reflection captures, rebuild lights (not that it should matter but you never know).
I would also try to add some geometry behind it, see of it’s actually there but not reflecting or almost entirely translucent.
Check wireframe view to make sure its there (altough since the shadow is, I assume the mesh should be).
Make sure the project has raytracing enabled?

That’s all the ideas I can come up with atm.

Hello MostHost,
The material I used is the glass material from Epic’s starter content. And the map, as you can see, is the scene is a “default new level” map. Since all is in RT, there is no refelection capture (and yes, RT is well activated!)

No, there is something wrong with translucency… But what?

It can be reproduced with Hdri Backdrop, in a totally blank project :

  • create new empty level
  • add Hdri Backdrop
  • Add post process volume (unbounded) > activate ray tracing for translucency
  • Add a basic sphere with M_Glass (from starter content)

Everything works well in editor, but since PLAY button is hitten, sphere is still present but is not displayed anymore in the scene.
Note that with an opacity set to 1, issue persists!!!

Definitly, I missed something…

Wow…
I don’t know why, but I noticed if my test level has not game mode and use the “default pawn”, translucency have issues and are not displayed.
If I set a new “default pawn” with no sphere as mesh component, translucency surfaces are displayed as intended.

What is the relationship with Pawn’s mesh component and translucents surfaces???

It was indeed a bug, fixed in 4.23.1 : UE-79849 Ray tracing translucency does not work in PIE with the default pawn

Thanks,