I’ve had this issue before in various guises, but always thought it was something I was doing. But this example seems to me to show this as a bug.
I’m trying to use a mask on this footage to ‘roto’ out the guy in the blue shirt and you can see in my first image the mask, with feathering that I’ve made.
However when I comp in the background plate without the guy, his blue shirt is still quite visible around the back of the chair, when the inner line of my mask clearly finishes inside the chair edge.
Does anyone know if I’m doing something wrong, or if this is a bug/know issue? It really seems like the mask controls don’t correctly align with the footage.
Compositing setup: The scale nodes are because the footage is 960x720 ‘anamorphic’. The lower image node is just a loop of a few frames where blue-man is out of shot.
So often the way, I think I’ve solved this 10mins after posting, at least for now.
FYI it seems to be related to the non-square pixel aspect ratio, and maybe I need to talk to the devs about how this is done as there is probably a better solution, but for now the workflow seems to be:
Do the roto in the movie editor with the original pixel aspect (I had it corrected to 1.25:1 to display correctly)
Rather than scaling the footage in the compositor, then combining it using the ‘correct’ aspect ratio mask, combine/mask the squeezed layers then scale the result.
This is still a bit of a workaround, and means I have to roto with squeezed footage, but that’ll do me for now
Hm, I am pretty sure this is a bug.
I tried with footage from Hollywoodcameraworks, which is anamorphic too, and it seems impossible to match footage and mask in a sane way. Here’s a file demonstrating the issue: http://cl.ly/2P1W44412o12
I suggest you write a bug report. Maybe attach your file, or if you want, you can also use my file as a demo too.
Yeah this drives me crazy as I use standard definition anamorphic video at work. And translating or positioning items in anamorphic is a pain too. Just having canvas awareness with interactive mask tools would solve many issues.
Just for reference, if anyone else comes up against this, it was partly my error. In the movie clip editor while making the mask, I had set it to x=1.25 when it should have been 1.33.
And so the steps for rotoing this anamorphic footage were as follows:
Import clip into movie clip editor
In the display/aspect ratio settings set correctly for display (my footage was 960x720 for final 1280x720 render, so set x to 1.33 i.e. 1280/960)
Create roto mask as needed
In compositor scale footage element/s with scale node set to: stretch to render size
Use mask node as factor or whatever is needed after scale nodes
I’m sure there are other issues with this workflow that 3pointEdit and others may have had, but I think this adequately solves my original issue. Hope this helps someone.
