Would one of the Epic team familiar with the TranslucentRendering.cpp and DeferredShadingRenderer files be willing to give a rundown of what needs to be adjusted to manually restore the SceneColor node’s ability to see Translucent objects? Or alternatively re-add the functionality behind a CVAR as was previously attempted?
Zach Bethel appears to be active in the relevant parts of those files, but I don’t know if anyone else could step in to hook us up with the info or bool checkbox option.
Currently the only way to do object-based (i.e. not PostProcess) material blurring effects is through use of the SceneColor node. From 4.0 to 4.16 SceneColor was able to “see” other Translucent materials in the scene, but then in 4.17 this was inexplicably changed.
All attempts at reaching out to Epic for the last half decade have gone unanswered.
Here are a small collection of use cases. Most are either tied to ArchViz rendering or game VFX work using selective local blurring effects.
One user, Mathias Hübscher, even created a wonderful little cvar to allow this functionality to be restored back in 2019, but his merge request was ignored. At this point the relevant files have changed so much since that it’s difficult to piece together the changes and how to properly socket them into the latest UE5.0.x builds.
Here are additional relevant links:
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One of the earliest posts from 5 years ago with several asking about the change in behavior.
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Thomas Kole’s excellent Custom Motion Blur Marketplace effect. The Q&A section has users from 2021 and 2022 asking about support for transparent/translucent objects, which would work if we had the option to restore previous behavior.
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The Documentation page for the previous Custom Motion Blur effect.
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Pedram Navin’s great Frosted Glass materials on the Marketplace.