HDR environment not showing in reflection pass when denoiser active

[Rchv]

When I enable the Vray Denoiser pass (with default settings), the HDR environment doesn't show in the (raw) reflection pass. So the pass shows reflection alright of the geometry and scene itself, but not the reflection of the HDR sky.

When I disable the the Denoiser, it renders fine.. Is this a known issue or does anyone know a solution?

3d Max 2023 and Vray 6 update 1.2

[hermit.crab]

It is normal. The denoiser adds a reflectionFilter element, which allows V-Ray to derive the raw reflections from VRayReflection internally (VRayRawReflection = VRayReflection / ReflectionFilter). The derived raw element is the correct one with the consistent elements option enabled.
Quoting the big yellow paragraph from here: "The raw elements are affected only when the corresponding normal and filter elements are available, otherwise they're rendered as before. This is because the raw elements have to be derived internally from the corresponding normal elements in order to work with the consistent elements (e.g. VRayRawGlobalIllumination = VRayGlobalIllumination / DiffuseFilter)."
It is possible to manually create the "pre-denoiser" element in post like this: (Reflection + Specular) / ReflectionFilter. The element will contain all reflections (direct and indirect).

[Rchv]

Thanks for your reply and explanation.

It is possible to manually create the "pre-denoiser" element in post like this: (Reflection + Specular) / ReflectionFilter. The element will contain all reflections (direct and indirect).

I've been trying to recreate this in Photoshop but unsuccessful - are you refering to blending options of layers, if yes what types?

[hermit.crab]

Thanks for your reply and explanation.I've been trying to recreate this in Photoshop but unsuccessful - are you refering to blending options of layers, if yes what types?

Okay, I did a few tests and it seems it won't work as described above since there's no "VRayRawSpecular". As mentioned in the advanced back to beauty docs page, you can only recreate the VRayRawReflections without specular (as the Raw result withotu denoiser), however, there's no real benefit in doing this since you can simply add it prior to rendering. Otherwise, yes, I'm talking about blending modes. In PS, Linear Dodge (Add) is equivalent to "plus" and Divide is, you guessed it, divide.