Vraylight reflection has black edges

[soulburn3d]

So I notice that if I have a reflective surface that's reflecting a vraylight Plane, it has black edges around the edge of the light reflection. Any idea why this is happening and how to fix it? Is it some sort of overbright issue?



- Neil

[Bruce Hart]

Have you tried to turn on Sub-pixel mapping?

[soulburn3d]

Yup, doesn't solve the issue. But thanks for the suggestion.

- Neil

[soulburn3d]

Here's a repro scene. It's so simple to reproduce I'd be shocked if other people haven't seen it before.

[joconnell]

sharpening aa filter causing some ringing?

[soulburn3d]

That was it, thanks. Guess mitnet doesn't deal well with really bright objects. Will have to do some experiments and settle on a different aa filter as my default. Thanks for figuring it out.

- Neil

[joconnell]

Yeah - mitnet pushes the bright pixels up and dark pixels down along the edges kind of in proportion to the values of the pixels. If you've got a reflection of a light with a multiplier of something way above one, it'll push down the pixels along the very bright edge by an appropriate amount to increase the contrast, but the really bright whites will push down the darks by more than a slightly bright white - here's the mitnet filter shape:



All the pixar stuff is mega sharp but would you be better off using something like area that will burn in less contrast / artifacts and then doing a slight unsharp mask in post?

[soulburn3d]

Well, this isn't for pixar stuff, this is for my home use.

Mitnet was the default aa for brazil, and I never saw artifacts like these. But that may have just been circumstantial, since my overbright cards tended to be say 10x the brightness of white, whereas the vray area lights tend to be hundreds of times brighter than white (and hence more likely to reveal the black artifact).

I like the sharpness of mitnet, did a few tests last night and found I can get something similar with area set to 1.0 or vraylanczos. I know setting area to 1 may cause some jaggies, but since my primary use is stills, it probably won't be a big deal. But I'll keep an eye on things.

Thanks again for the help.

- Neil

[vlado]

You will get this with any sharpening filter; a solution may be to clamp the output from the color mapping settings, but of course you lose the HDR information.

Best regards,
Vlado

[soulburn3d]

You will get this with any sharpening filter; a solution may be to clamp the output from the color mapping settings, but of course you lose the HDR information.

Ya, wanna keep my HDR, so I'll stick with the smaller filter width on Area filter for now and see how that goes. Thanks Vlado.

- Neil

[Deflaminis]

A lot of the post glare software/plugs will erase the black edges sort of automagically. (starglow)

[eyepiz]

hide the light and use a light material...that usually works for me.