Making Clean Hair Particles

I’m finding it difficult to make these hair particles do what I want. I’m using a density map to stop hair from emitting in the desired area, yet still it decides to emit a few sporadically and the edge between the two areas is really horrible. I’ve tried boosting the amount of particles but it doesn’t appear to really help. I could use some pointers. Thanks in advance.

Attachments


try to add hair to specific vertex groups and let the middle square out of both. on the hair emission, there’s a setting to change to have a more even distribuition.

on the child settings, see this one:
RoundnessThe roundness of the children around their parents. Either in a sphere (1.0) or in-plane (0.0).
https://docs.blender.org/manual/en/dev/physics/particles/hair/emission.html
https://docs.blender.org/manual/en/dev/physics/particles/emitter/children.html

Use vertex groups, and make some really tight loop cuts right at the boundary. Hairs spill into the adjacent faces, so the hack is to make those faces tiny.