Does anyone know how scribbly pencil effects like these are composited?
It's clear in the final version that the lines are composited as a raster, but then how does that play with the less wild lines (on toji's face, for example) that have clearly been vectorized? How are some regions of the image selectively vectorized while others are taken as raw raster data?

Are the scribble effects drawn on a different sheet and scanned separately? Or do the satsuei people just manually mask out the scribbly regions? Is software used to separate out the two automatically? Or is it something else entirely?

haikei_douga said:
Does anyone know how scribbly pencil effects like these are composited?
It's clear in the final version that the lines are composited as a raster, but then how does that play with the less wild lines (on toji's face, for example) that have clearly been vectorized? How are some regions of the image selectively vectorized while others are taken as raw raster data?

Are the scribble effects drawn on a different sheet and scanned separately? Or do the satsuei people just manually mask out the scribbly regions? Is software used to separate out the two automatically? Or is it something else entirely?

Here only main animation got cleaned up, the scratchy lines stayed the same and probably got traced and added as sperate layer over the final animation

To further expand, yes some of the wind effects and speed lines are drawn on other sheets of paper. Here in this post they’re composited over the other layers by changing the blend mode (probably to multiply. If you look at the edges of the frame you can see where the pages don’t quite line up). In the final version they’d each be on a separate later and placed on top of each other.

Also, afaik, nothing in anime is vector based, everything is raster. The look of the lines and effects is also impacted by the compositing instructions and other notes Kato would have included on the timesheet, and of course the choices of the episode director, series director, and director of photography on how to process the cut further.