roto mask edge noise

[Eneen]

Please take a look @ screenshot:

I seems some kind of noise is added to bezier roto, but I think this is case when there should be nicely anti aliased straight edge.

Natron V. 2.2.5, Windows 10.

[MrKepzie]

You need to set the Feather parameter to at least 1.5 px

[Eneen]

It is 1.5px.
Setting more causes edge too smooth but still noise is visible.

[MrKepzie]

Can you show the settings of the Roto node itself and the alpha mask in the viewer directly ?

[Eneen]

Sure, here you go:

To be sure I've made new roto.

[MrKepzie]

Fixed by 49981cc

Note that there are still a few minor artifacts that are due to a bug in the cairo library.

In Natron 3.0 we moved away from cairo anyway and the Roto is fully implemented in OpenGL (GPU accelerated) so all these artefacts should no longer be an issue.

[Eneen]

Thx alot! I can also try to report bug to cairo but I need info what to report.

[MrKepzie]

I did not investigate further but it seems that the rasterisation of coons patch with very sharp angles produces artifacts.
Anyway I can't spend more time on this since we don't use it anymore as of Natron 3