In the Unreal Engine NvRTX Caustics version, when path tracing is turned on, specular light cannot be seen

The first image is in normal lighting mode, with normal light reflection. The second image is after turning on path tracking, and the reflected light cannot be seen

Hi there @Jaxxx, welcome to the NVIDIA developer forums.

Can you please share which Caustics branch you are using?
And when you say “path-tracing”, do you mean the UE built-in path tracing option?


My Caustics branch version is NvRTX_ Caustics 5.1, “path tracing” is UE built-in path tracing, and its activation method is shown in the image.

Thank you!

One thing to try is to upgrade to the 5.2 version of the Caustics branch if possible, it was recently updated.

And then i am also not sure how well our Caustics integration plays with the UE path-tracing implementation. It is very well possible that there are internal conflicts.

Maybe @jackwang1 knows more about this?

Hi @Jaxxx We’ve never touch the relevant code in path tracing module, I’ve double checked the vanilla UE 5.2.1 behavior that is identical with our NvRTX Caustics branch. Cheers.

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Thank you. I will try it.

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