Denoiser causing artifacts in glare

[busseynova]

I have a 32bit comp set up in after effects and was planning on using the VDenoiser (Vray Next) on the renders from Vray 3.6. I believe this might not be a problem if rendered with next, as you can isolate the glare channel and use an ADD function in AE, but as it is I'm using LIGHTEN on top of the comp. The comp is not particularly complex, so I could probably revert to just using the glare channel as my main RGB, but this problem will remain.

As you can see below, the denoiser causes some artifacting where it's conflating the glare with the reflections and other light sources. I have the glare clamped to a material ID.

Is there any other way around this? I really like the glare effects and denoise is essential on this project, but the two aren't playing well together in this instance.

[busseynova]

Ok, after a bit of experimentation I think I've got it. If I subtract the noisy RGB from the noisy Glare, it gives me a non-noisy glare effect in isolation. I guess as the Glare is an post-effect, it is immune to rendering noise. I can then add this (linear dodge) back in to the de-noised comp.

PHEW. Problem before was that I was trying to subtract a denoised RGB from the noisy Glare pass, which gave me glare plus a load of noise, which was then being added back in.