Hi Martin.

My problem with path is resolved.

Glad to hear it. [:)] You could perhaps show us what happens in this project or another. [;)]

Please can you explain me the real difference between multipass and bucket except pre-defined antialiasing? ... And what is the pre-defined AA in multipass?

Hmm, good question. I have not found this info even in the source code of Sunflow .

And the last question...If you can tell- what's your favourite filter?

My favorite filter is Mitchell. I found that some filters use a blur more or less pronounced compared to others.
Here is a ranking based on the visual differences:
1_ blackman-harris, bspline
2_ gaussian
3_ mitchell
4_ triangle
5_ catmull-rom
6_ sinc
7_ lanczos
8_ box (anti-aliasing ignored)