Most automated cross-hatching is bad. Photoshop crosshatching brushes just create ugly messes that could only be convincing to people unfamiliar with drawing. I created my own technique for automating part of the process – but ultimately there’s no way around the fact that if you want something to look like it’s been drawn well, you have to be able to draw well.
For a while, I’ve wondered if this technique could be effectively utilized in animation. For this experiment, I drew a full sheet of hatch marks. Then I brought this into After Effects and used some scripts to automate their position and rotation values within some narrow parameters. I also set the project frame rate to 10fps (‘on threes’ in classical animation parlance – although that would more likely have been 8fps since they were dealing with film). The lower framerate is important to convey the effect – it’s what people are used to when seeing most hand-drawn animation, and a faster framerate would make the hatchtone movements too noisy and incomprehensible.
The same setup might work for some other natural media once the tonesheets are drawn… graphite, colored pencil, crayon. But the sharp edges of the posterized grey tones might be a drawback. It works all right for the cross-hatching because we’re used to seeing a fairly sharp end to pen and ink lines.
The test footage is a realtime hardware render in Maya, run through my processes in After Effects.