Need help figuring out how to do proper line art colour overlay


I’ve been trying to mess around with the colour override and cutter filters for a few days now and I can’t seem to get the effect I want. The character that I am rigging is single-tone (red, mostly) and I want the line art to be alpha’d to zero when it’s not overlapping other body parts like the torso or the head (I’m exporting them into png sequence into After Effects where the background colour can vary greatly). Like in the image attachment, I want to have the line art fully visible when it overlaps the torso, head, or the opposite arm.

Any suggestions? I’m willing to approach this problem at a different angle if it can get me a similar result.

Thanks for reading!!

One thing you can do is to isolate both the color and line art of your arms drawings using the nodes you can find under "“filter > isolate”
This way, you can split your drawing like in two different layers. The color goes direct to the composite while the line acts as a cutter to the torso/head drawings.