Sculpting (heads and characters, Blender 5.2)

Expert sculpting is structure first and surface last: masses blocked with stated planes and corners, proportions locked at low resolution, every stage judged by eye through a long lens, and appeal as the final test, not the mesh numbers. The agent builds blockout and primary forms headless (scripts/bx_sculpt.py: smooth-blend Clay, plane cuts, numpy brushes) and does client-quality surface work with Blender's real brushes in a live GUI session (bx_gui). If a sibling skill named here is missing from your available skills, ask the user to install it (npx skills add scenario-labs/skills --skill <name>); unattended, proceed from tool schemas and flag the gap.

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

Stance (the expert delta)

• Planes are stated, not found. Thelen cuts plane borders with Draw Sharp and re-cuts them whenever a face "looks off"; Naydenov simplifies into planes, then smooths; Reinhardt uses Scrape, Trim and Line Project for clean cuts. Executable form: give the plane (point + normal) to Clay half-space clips or plane_cut / corner_cut. A flatten or scrape dab fits its plane to the ball under it, so it follows the ball.
• The jaw is a block with a gonial corner, the cheekbone a mass with its own lower plane. Zarins: the gonial angle is the age and sex dial, steep in adult males; the widest face point is the top of the zygomatic arch. Naydenov: the cheekbone runs from the ear down and forward, only its lower edge shows. Thelen: bone plus tissue, never razor sharp.
• Fix mass upstream; planes only restate. If re-cutting planes does not fix the look, the problem is mass or proportion (Thelen's diagnostic). Measured: plane cuts on a balloon jaw flipped the form metric but rendered as a gem facet; rebuilding the jaw block fixed it.
• Low resolution as long as possible. Abbitt: smoothing is strong only on big polygons; Thelen: lock proportions coarse. Symmetrize after every remesh (Keelan Jon), then a global relax (Kaspar FDscc66fC90 00:11:55).
• Indicate small landmarks early (nostrils, brows, eyes): Yan found a too-wide nose from the nostrils (vB7kPWjBgQI 00:05:11).
• Stylize by consistent exaggeration (Yan: pick it in minute one, make neighbors follow; a long face needs a smaller skull, not a stretch).
• A concept head needs its cues. Thelen: hair makes a male head read better (00:48:58); Naydenov: hair changes the read a lot (00:53:05). An "adventurer" with no hair or costume reads as a bald mannequin.
• Asymmetry and expression live on a shape key; the basis stays neutral and symmetric (Kaspar f-mx-Jfx9lA 00:09:44; Thelen 00:38:27). Expression tests expose proportion errors; fix them in the neutral (Kaspar 00:10:49).

Establish first