DOF Artifacts

[Komposer]

here is the next heavy problem with DOF!
It´s a simple scene - 3 Balls - physical Cam with DOF - simple vraymat - no animation.
I saw this prob in the first cam-animated testrenders of my master scene - and build this simple scene for testing!

When I step from fram 1 to 2 and then to 3 - In every different frame (again, here is no animation!) I get a different ugly result!
...the screenshots show it clearly!

It´s the same with the official 3.0!
And it happens with- and without DR-Render.

What could be wrong here?
Please help soon - I can´t start final rendering...
Thanks so much!

[ivaylo.ivanov]

You must increase your minimum samples and/or decrease adaptivity. With small buckets and difficult sampling like DOF, motion blur, volumetrics, V-Ray may cast too little rays and miss scene objects.

[vlado]

Another alternative is to use the progressive sampler. Because it looks at the entire image, not just buckets, it is also able to handle such cases somewhat better. If this is not possible, then increasing the min. subdivs for the image sampler is the only other workaround like Ivaylo suggested.

Best regards,
Vlado

[Komposer]

Thanks guys, that helps.
After setting min Samples to 3 it renders perfect, but 20% slower - but thats fine for me! puhhh
I made some test too with decreasing adaptivity - nothing made a difference.
How would You decrease adaptivity?

[ivaylo.ivanov]

The DMC adaptivity and bucket size affect this limitation, but in a more complicated way. Bigger bucket size means that V-Ray will look into more pixels to find a difference between pixels and cast more rays. The bucket can always happen to be at the "wrong" position and miss something though. Lower adaptivity/higher min samles means that V-Ray will cast more rays before giving up, so there is a bigger chance to find something. These are advance DMC settings:

http://docs.chaosgroup.com/display/V...mpler-advanced

You can play with them, but increasing the min image samples/using progressive sampler are more robust solutions.