Hair Tool is addon for Blender 2.93 that will help you generate hair-card based on 3d curves in non destructive way. (For blender below 2.93 you can still use HT 2.27)
Three main ways to generate hair-cards with Hair Tool:
using guide mesh (grid surface)
using particle hair interactive grooming
by drawing hair strands (similar to Grease Pencil drawing)
Some of the features:
automated UV workflow (random uv region assignment per hair strand)
texture preview directly on curve ribbons
curve modeling tools (extend, shorten, cut, move hair with IK physics)
go back and forth between curve and mesh ribbons
adjust ribbons profile (tapering radius, randomizing tilt, editing profile etc.)
convert: Curves to Particle Hair, Particle Hair to Curve ribbons, Curve ribbons to mesh ribbons and so on.
curve resampling and decimation (increase/decrease curve/ribbon points count)
generating vertex color/weights gradients, transferring UVs and vertex weights from character to mesh haircards.
texture baking (from curves or particle hair; supports: normal, ao, diffuse, tangent maps, ID maps, root map etc)
build-in addon auto-updater
and more ma g.