Hair and fur grooming (hair curves, Blender 5.2)

Version 0.1 (2026-09-24), part of Blender Expert Skills v0.1.

Expert grooming means a few evenly spaced guides that set direction and silhouette. Stacked, masked procedural layers add density, clumping, frizz, length variation and strays, judged in a lit render at full density and in pose. Write guides as data (no curve brush stroke can be scripted in 5.2.1) and make every look decision through the Essentials hair node-group assets.

REQUIRED BACKGROUND: blender-expert (execution channel, review loop, 5.2 API changes).

Stance (the expert delta)

• Guides get 2 points until every direction is right (Schmidbauer). More points make combing tangle and clip. Use 3 for short fur, 8 only for long hair. Bystedt resamples long human hair to 15 points before shaping.
• Space guides evenly, and always mask Interpolate (Schmidbauer). Children spawn over the whole surface, and a child far from any guide "does whatever". Gaps turn into bald spots that grow under deformation.
• Density is counted per square metre and must be huge. Radius drops with it (Thommes). Long fur uses 1,000,000/m² at about 0.2 mm radius. Work at a Viewport Amount of 4%.
• Randomize per curve, not per point (Thommes). Give 80% of strands no frizz. Strays are 10% of curves with strong noise.
• Trim with Replace Length off plus a Random Offset (Schmidbauer, Thommes). It is the cheapest realism gain. Mask it, or short-fur regions lose their guides and go bald.
• Grow a human hairstyle on a separate hair cap split along the part (Bystedt): body topology stops mattering, interpolation stops crossing the part. The part still needs extra density and a lift.
• Shape works the same way on every asset: 1 affects the tip only, 0 the whole strand, negative the roots. Use a negative Frizz Shape so curl and clump tips survive (Thommes, Bystedt).
• Judge renders at full density, and in pose (Thommes, Schmidbauer). A harsh mesh deformation "looks ten times worse" in the hair.