AA - blackman

[rajdarge]

I am having problem with my favorite AA filter. In fact every filter xpt the ones on the list below Lancoz etc don't work


Lights reflected in metallic material object have black rings around them.


I look at the values in the VFB and the colour values around the highlights are negative values
I expect this is causing the black rings around highlights.

I don't like the ring, triangle sync or lancoz filter, as they tend to blur the image, and leave jaggies.
Raj

[dlparisi]

This has been answered before...

Sharpening filters also have a nasty habit of causing serious edge artifact when you have bright areas like a high reflections of a light source or sun next to a darker area. This was not an issue before real world lighting. However, because in Vray everything is rendered in float (with 0 being black and 1 being white) the bright area could be a value of 5 and the dark 0.02. The sharpening filter will get you an "error" at that edge actually giving
you negative values basically looking like a nasty black edge.

This can actually be avoided by using a smoothing filter and, if sharpeing is needed... do it in post.

The bright spots are reflections/hilights from the sun. You can also use the clamp output/subpixel mapping options in the Color mapping rollout to deal with the issue.

Best regards,
Vlado

[rajdarge]

thanks - sorry, I did a search for the answer, didn't find it.
This Forum needs a topic index.




actually the problem is not restricted to the Vray/sun sky - it occurs with ANY light.

Raj

[rajdarge]

I didn't have sub-pixel on - now is fixed
Raj