When the script finishes, you will have a new folder full of cutout PNGs. Back in Resolve, go to the Media page, browse to the output folder, and make sure frame display is set to sequence so Resolve reads the images as one image sequence clip instead of individual still frames.
Import the processed frames
Import that image sequence into the project, then use it as your alpha matte on the Color page.
Use the sequence as alpha
Once connected properly, the cutout sequence acts as a mask for the original video. This is where the workflow starts to pay off, because the roto can look extremely solid right away.
Replace the background in Resolve
To preview the cutout properly, add a different background color behind it. In Resolve, this is done with a layer mixer.
The basic node flow looks like this:
- Original footage as the foreground
- A color generator as the background
- A layer mixer combining both
- Main output from the layer mixer
If highlight mode is still enabled, turn it off so you can see the actual composite. Once the background color is in place, any problems in the mask become much easier to notice.
On this shot, the composite looked strong with a flat light-blue background, and the roto remained stable through motion.
