How can i switch from lumen to raytracing?

Hey i’ve got a strange problem. I work on a scene in vr, and i learn recently that it’s a wrong idea to use lumen for that. I want to change to raytracing but the option cannot be selected.

Someone have an idea ? i search but i cannot find a solution.

thank you and sorry for my english


If the GI/reflection options are greyed out, it means they are disabled such that they’re not even available to begin with. This means some engine configuration more fundamental is overriding the option. By and large though, lumen and ray-tracing share a lot of the same pipeline (relatively speaking).

For example, if you’re using forward rendering for VR performance reasons, you can’t change the settings because no dynamic GI or reflection method is allowed. Lumen/RT also won’t work unless you’re using Directx12, or perhaps Vulkan. Either way, you can’t enable the options unless you’ve configured the engine to allow them to begin with.

One note however: if it’s a wrong idea to use lumen in a scene for performance reasons, it’s probably a bad idea to use ray-tracing as well. Lumen is more optimized and scalable than RT, espectially to lower-end consoles. If, for example, you wanted RT reflections with baked GI however, that’s understandable, but you might not be able to afford the performance hit in VR.

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