Noisy highlight

[Micha_cg]

Hi,

I try to get a highlight effect of a point light at a glossy material, but the highlight looks very noisy. How to avoid the noise? Bug?

Micha

Rhino file
www.simulacrum.de/download/NoisyHighlight.rar

[dalomar_cg]

Re: Noisy highlight

Micha,

I'm not sure whether this is a bug or not, but at the heart of the issue is trying to do highlight glossies with a non physical light. There are two things I observed while looking at the scene. First was the noisiness, which couldn't be fixed with either mat subDs (you had tons on there) or better AA. The second thing was that the actual highlight area was much larger than it should have been for .95. I think that there whatever does the sampling for highlight glossiness isn't setup properly to deal with point lights. I'd submit a bug report just to make sure its there, but I think this is something that goes back to Vlado. Either way, when they are available, I would recommend using a sphere light with a very small radius.

HTH

[Micha_cg]

Re: Noisy highlight

Thank you Damien. The highlight size is so big, because I set the point light radius at a high value. It's nice, that the highlight size is dependent from the light source. At my other renderman standard render engine it isn't the case.
If I understand right, highlights are not computed by QMC blury effect calculation, so it's ok, that subdivs and noisethreshold show no effect.
From the history of rendering it's an old technic. I'm curious what Vlado think.