Issue with Paint Groups

Hi all,

I'm new to Fusion, but found some wonkiness that I don't think is my noobdom, so I thought I'd ask.

I have a project where the back wall behind some singers has some blotches, so I brought them into Fusion to paint them out. Took around 15 Clone strokes or so, and there is only some subtle camera movement. I tracked a larger blotch, then selected all strokes and grouped them into a paint group, connected it to the tracker, set my offsets, and everything looked good. Then I tried to render, and the strokes randomly jump around, blink on and off, etc. Plays totally perfect in the RAM preview. I tried different output formats, deleted and reloaded a new saver...nothing helped.

Weird, right? So I started over, and tracked each stroke one at time, and it worked fine. Then did a quick test, where I did a squiggle, tracked it and rendered...all good. Went back, put that ONE stroke in a paint group, same issue...stuttering, blinking, jumping all over.

Is it buggy, legacy, or is there something I don't know about yet? Not a huge deal for now, but when I run into 50-60 strokes I need to group, I'd love to know how to not to have to deal with those one at a time...

Thanks in advance!
Mark

What is the format of your source footage? What you're describing is definitely buggy, it's also legacy, but there are factors that make it happen more often. For example when working with movie formats instead of image sequences the behavior you're describing happens more often.
Also when working with clone strokes it helps to specifically drag your source into the requester for source images. It should work automatically, but doing it specifically seems to help with stability in cloning.

Why is grouping important for you? I'm asking, because in the 15+ years of using Fusion paint I've personally never grouped a stroke before.

I've seen the same issue.

When doing precise cloning or beauty work I generate many individual strokes, but need to track them as a single entity. Is there a better way to accomplish this?

Hi Sander,

Thanks for the reply. The movie files are simple Prores 422 HQ Quicktimes. As Igor said, grouping was important only for the fact that I had many strokes, but the camera is moving only slightly, and one solid track with one or 2 points would've covered it. Again, it looked perfect in the RAM preview, and only screwed up in the actual render. I ended up tracking each stroke, which took a bit longer and made the viewport quite a mess with all the tracker boxes, but it worked. Again, not a big deal, but this is likely the easiest Roto I'll be doing, so I'm trying to figure out how to work reliably when I have more difficult shots to deal with.

I'll try what you suggest, by manually dragging the clone source in, and trying with image sequences. I'd also be interested to know if there's a better way to have multiple strokes follow one track without grouping. I tried using "Connect to" the same trackers, but since the center offset is in the tracker itself, it wasn't really an option.

To be honest, the way I wanted to originally approach it, was to track with a transform node, set to "Steady Position" and another copy using the same tracker data set to "Unsteady position," and do the cloning on the static frame with the motion temporarily removed. Unfortunately, as soon as I added a Paint node in-between the 2 Transform nodes, it seemed to ignore the tracker data.

The last part you wrote was more or less on the right track (pun intended) but even that is more difficult than strictly necessary. In Fusion there are usually many different ways to achieve a desired result and everyone has their own preferences. So my suggestion may not be the best, but I usually branch off the source image and do my painting over a blank background or after a BC tool with the gain set to 0 and alpha checked. This will create an empty canvas for you to work on that always stays at the correct resolution. (this one I learned from Eric Westphal).

So I'd paint over the empty background with the clone source set in the way I described and then I'd use a transform tool and connect the center/pivot/angle etc to your tracker. This way the transform effectively functions as a group transform, so there's no need to attach every seperate stroke.
That should make the painting follow the shot. If for some reason it gets off-set just pipe it into another transform to change the global off-set. Because of Fusion's concatenation you won't see any image degradation when you daisychain those transforms.