5.3 Lumen Reflections with baked lightning.

Hi, I’m working on a project relying heavily on reflections, but with no use for dynamic lighting and global illumination, so I was delighted to hear of the new beta feature of 5.3 that enable Lumen reflections compatibility with baked lighting.

Blockquote

  • Lumen Reflections can now be used without Lumen GI, for games and applications which use static lighting but wish to scale up in reflection quality beyond Reflection Captures. Standalone Lumen Reflections only work when Hardware Ray Tracing is enabled, and it will force Hit Lighting to be enabled automatically, as Lumen’s Surface Cache optimization is not available when Lumen GI is disabled.

I tried it out, and I have a few questions on whether some of the behaviors of this feature are expected to stay the same on release, or if they may be improved for the final version.

First of, I realized I must disallow Nanite on my meshes, otherwise they wont appear in the reflections, I don’t have this behavior in my scene with Lumen enabled, so is it a normal behavior or to be expected with the lack of Lumen ?

My scene with full Lumen reflections, GI and lighting enabled


My scene with Lumen reflections but baked lighting and no GI + Nanite disallowed on every meshes

My scene with Lumen reflections but baked lighting and no GI + Nanite enabled on some meshes

My second question is on the fallback in case of no raytracing capabilities. Lumen reflections as a nice fallback solution in that case with (a sort of dynamic cubemap + screen space reflection if I’m not mistaken ?) but if the lighting is baked, there is no cubemap, only the screenspace reflection, is it an expected effect of the lack of Lumen ? That one is less troublesome because reflection captures can be place in the map though.

My scene with full Lumen reflections, GI and lighting enabled, but reflections set on medium


My scene with Lumen reflections but baked lighting and no GI, and reflections set on medium

Thanks for the read.

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Hi, can I ask you how did you enable Lumen in a scene with baked lighting? I can’t seem to make the Lumen reflections work. I enabled raytracing and everything but reflection type in post-process is set as Lumen but greyed out. And reflections are not working. Is there a tutorial or something or did it work for you by default?