Clamp Output / 0N - OFF

[alex.nozadze]

Hello ,
how to avoid antialising in bright areas without switching on clamp output ?


Glare with intensity not working when Clamp output is on ,

thanks

[Neilg]

clamp to 4?

[alex.nozadze]

clamp to 4?

I have try already , but same result ...

[alex.nozadze]

I don't understand, why Vray makes that "stairs" (no-antialiasing) in bright areas without clamp output on ...

[Ihno]

Because vray is averaging the results of the samples,
say the first hits the wall behind the light and returns 0.5 brightness the next hits the light and returns 8. That would make 8+0,5/2 = 4.25 which would still be white. You'd have to perform a huge amount of samples to get an antialiaized edge. It probably dosn't work exactly like that but that's basically the problem here.

You can fight that by dropping a VraySoftbox map with frame vignette in the texture slot of your light. But that will change the lighting slightly.
Edit: its not the border of your light which is causing the problem here, so this wouldn't help. Sorry for not reading your post very carefully.

[Alex_M]

It's hard to tell what's that bright part in the screenshot but if it's a vray light then make it invisible, make an object with the same shape and size and apply a vray light material and make it not cast GI, shadows, etc. Don't forget to exclude it from every light in the scene so that it doesn't block them. This way you can make it a low pixel intensity but still appear white so it's going to be easier on the sampler to anti-alias it.

If it's not a light, try different anti-aliasing filters and filter settings to blur it a bit. AFAIK, Soften filter with size of 5 or 6 is very good for softening around very bright edges like your case.

Other thing you can try is use DOF so that this part will go just ever so slightly out of focus if that's not a problem. I think the DOF should smear it a tad and smooth it out. When you don't use DOF, everything is in focus and laser-sharp which is not how real world cameras work hence the artifacts around very bright edges that we all dread.

[svetlozar.draganov]

This is a general Image Sampler issue with every render engine and the problem is because the difference between the darker and the brighter part of the image values.
The image sampler itself cannot get a smooth result when pixels from one side of the fence have a value of 0.2 and from other side the value is 10 or even more.

Like Alex_M suggested a Soften filter with large size like 8-10 for example might help to smooth that edge but it will also increase the render times and smooth out other part of the image which may be unwanted.
According my experience a small Bloom effect just to cover the jagged pixels is a much better approach since it doesn't require a increasing IS values which will also increase render times and it will only smooth out the brighter pixels in the image which is exactly what happens when shooting with real camera.

Here is a example of what I am talking about:

[alex.nozadze]

I have dome light with HDRI , and plane light behind window , DOF, bloom and glare ...

Soften filter - solution ,

Thank you all for suggestions !