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).
\nClay 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.| Input | \nChanges | \nDefault when silent | \n
|---|---|---|
| Who (sex, age, type, attitude) | \ngonial angle, brow, jaw width, shape language | \nadult male, neutral basis, stated [added] | \n
| Style | \nstylized: exaggeration table; realistic: canon + reference | \nstylized, \"abstracted enough to not be uncanny\" (Kaspar) | \n
| Character cues | \nhair, costume, props that sell the type | \nat least hair plus one costume signifier [added] | \n
| Purpose | \nstill (vertex paint, decimate) vs game or film (retopology) | \nstill; scenario-blender-retopology if animated | \n
| Delivery framing | \ndetail frequency, expression size | \nbust fills a 1080 px frame [added] | \n
| Scale | \nnothing if sizes are fractions of head height H | \nH = 0.24 m [added] | \n
| Channel | \nheadless numpy / Clay, or live GUI brushes | \nheadless blockout; GUI for surface when the bridge is up | \n
G = S.head_guides(H), a STYLE dict (the one or two exaggerations), the cue list, and the landmark points of the planes: gonion, chin bottom, cheekbone. GATE: written down.Clay. Cranium ellipsoid clipped by skull side and front-taper half-spaces; a jaw sd_round_box BEHIND the mouth mound, clipped by side, underside and ramus planes through the gonion; a square chin block; cheekbone ellipsoids along the ear-to-cheek line with a lower plane; mouth mound; brow ridges; nose; neck leaning about 15 degrees; ears; frontal box around the eyes. Blend big masses at 0.08 to 0.15 H, clip edges at 0.02 to 0.03 H. Option: union_remesh of primitives (rounded_box is a Catmull-Clark blob that reads as a ball: never use it for a jaw). GATE: 1 component; lower_face_report(head, H)[\"ball\"] False; silhouette plus 90 mm renders show a jawline and gonial corner in profile and three-quarter; the exaggeration visible.to_object(name, symmetric=False) for anything asymmetric). GATE: profile beats; eyes not marbles or bags; hair frames the face; stage_report clean.remesh_stage). Lines with crease_line (mouth, under-lip, lid rim) on surfaces facing the projection; nostrils from below. Restate planes with corner_cut / plane_cut only where the mass is right and moves stay small. GATE: under 100k faces (Abbitt), no scratches, cracks or rims in 90 mm renders.bx_gui (fixed and verified: strokes raycast onto the mesh and pass object-space locations; set_view(frame=obj) first, view_distance a few head heights). Headless numpy strokes suit blockout and primary forms, not polish. Multires only on a settled clean base (Henning Cmi0KoFtc-4 00:16:04).sc = S.Sculptor(head, symmetry_x=False), move_feature the corner, cheek, lower lid, opposite brow; S.write_shape_key(head, \"Smirk\", sc.co). Size the corner move to the delivery framing (Numbers). Voxel remesh drops keys: last step.S.final_render(objs, path, direction, lens=90, res=1600) (cavity, framed on real vertices) from front, profile, three-quarter, neutral and expression; open every image.Inside every stage: render, name ONE weakest link, fix it, re-render (Yan). A metric that passes while the render looks wrong means the render wins.
\n| Value | \nNumber | \nSource | \n
|---|---|---|
| Voxel ladder | \nH/40 blockout, H/65 to H/110 primary, H/130 to H/235 secondary, about H/330 detail | \nMorren, Abbitt; example | \n
| Faces from voxel | \nabout 1.5 x area / voxel^2 (voxel_for_faces) | \nmeasured, 3 % | \n
| Example bust faces | \nH/40 8k, H/110 64k, H/150 103k (with neck) | \nmeasured | \n
| Face gates | \nshape before 100k; detail about 500k | \nAbbitt | \n
| Raw remesh mirror error | \nmax 0.67 to 0.75 voxel, mean 0.05 to 0.07 voxel (nearest vertex) | \nmeasured | \n
| Clay blends (head) | \nmasses 0.08 to 0.15 H, plane clips 0.02 to 0.03 H, lids 0.012 H | \nexample [added] | \n
| Jaw | \nbigonial 0.90 to 1.00 x bizygomatic (example 0.93); ramus-to-base angle 124 degrees in the example | \nThelen; example [added] | \n
| Eyes (stylized) | \nradius 0.064 H, lids 0.012 H thick, upper margin 21 degrees above center | \nexample; 14 degrees read sleepy | \n
| Hair | \nclumps 0.065 to 0.115 H radius, rising 0.8 x radius, from the hairline back; base 0.008 to 0.02 H | \nexample [added] | \n
| Corner move that reads | \nabout 1/8 of mouth width (8 mm on 65 mm, 0.03 H); invisible at 1/30 | \nmeasured | \n
| Pixels per mm | \nbust fills 1080 px: 2.8; bust 270 px tall: 0.75 | \nmeasured (framing) | \n
| Smooth strength | \n0.2 (5.2 default 0.7) | \nHenning | \n
| Crease resolution | \nat least 3 to 4 vertices across the radius | \nRyan King | \n
| Review lens | \n85 to 95 mm perspective | \nMorren, Kaspar, Naydenov, Yan | \n
| Landmarks | \neye line 0.5 H; nose bottom halfway brow to chin; lip parting 1/3 nose to chin; ear nose base to brow; width H/1.5; mouth corners under eye centers; canthal tilt about 8 degrees; neck about 15 degrees forward | \nAbbitt, Naydenov, Thelen | \n
S.stage_report(obj, voxel) (components 1, non_manifold 0, stretch p95/median under 2.5, mirror_max under 1e-4 before asymmetry). S.lower_face_report(head, H): ball True means the lower face fits one sphere within 10 % and twice as well as a plane (calibrated: the three E2 balloon jaws 0.057 to 0.082, the baseline 0.18 to 0.20, the v2 example 0.23 to 0.26). S.profile_rhythm(obj): chin out, in, lips out, in, nose out (a nose hanging below the nose base hides the lip beats). sc.planarity(c, r) for a stated plane.S.long_lens_render or final_render at 85 to 95 mm from front, profile, three-quarter and below, plus bx_review.review(..., modes=(\"silhouette\", \"matcap\")) for the ortho silhouette. Order: silhouette, big planes (cavity off, or mode=\"flat\"), below and above, lines, character read at thumbnail size. Rubric: references/critique.md.| Mistake | \nWhat it looks like | \nFix | \n
|---|---|---|
| rounded_box or ellipsoid jaw, heavy smoothing | \nballoon lower face: cheek, jaw, jowl one sphere | \nClay jaw block with stated planes; lower_face_report gate | \n
| Flatten or scrape dabs to \"make planes\" | \nfacets that follow the ball | \nstated planes: Clay clips, plane_cut, corner_cut | \n
| Plane cuts on a wrong mass | \ngem facet with a rim, metric passes | \nmove or rebuild the mass first, then cut | \n
| Jaw block with its front ahead of the mouth | \na mask or slab over the lower face | \njaw behind the mound; front belongs to mound and chin | \n
| Tall jaw block, small blend | \na panel edge across the cheek | \nlow block, 0.15 H blend upward | \n
| Socket wider than the lids | \nring groove, eye bags | \nsocket 1.1 x eyeball, lid blend 0.012 H | \n
| Lids reaching behind the eye equator | \nsealed pocket, 3 components | \nclip lids at the eye center plane | \n
| Uniform hair offset, or clumps on a thick cap | \nhelmet ledge, beanie with worms | \nthin base, clumps make the volume | \n
| Clumps starting behind the hairline | \nbare headband over the forehead | \nstart clumps at the hairline | \n
| Symmetrizing asymmetric parts | \nswept hair mirrored, center seam | \nto_object(..., symmetric=False) | \n
| Crease projected across a grazing surface | \nparallel cracks | \ncrease only surfaces facing the view; skip it | \n
| Smile sculpted into the basis | \nasymmetry cannot be removed | \nneutral basis, write_shape_key | \n
| Corner moved 1 to 2 mm | \nexpression invisible | \nabout 1/8 of mouth width, check pixels | \n
| No hair or costume | \nbald mannequin | \ncue list in stage 0 | \n
| Detail before proportions | \nlines on a wrong skull | \nstay coarse until the gates pass | \n
| Stroke snapped with nearest from far away | \ngroove on the nose tip | \non_surface(p, view) | \n
| Mask survived the remesh | \na region refuses every brush | \nremesh_stage clears it | \n
| GUI strokes with the view zoomed out | \nwhole mesh flattened | \nbx_gui.set_view(frame=obj), check view_distance | \n
| Hairline as one tilted cut | \na garrison cap from the side, vertical wall at the front | \nhairline as a function of azimuth (sideburn, over the ear, down to the nape), quiff ramp from the hairline over about 0.12 H [eval] | \n
| Mirrored eyes | \nno gaze, a staring or blank attitude | \ntwo aimed eyeballs; lid margin and brow angle are attitude dials (level brows for a neutral basis) [eval] | \n
| Feature attached at two points | \na nose that floats in profile, see-through gaps | \nray-grid silhouette-hole probe per view; give a big nose a side wall to the cheek; bx_audit self-intersections after the last remesh [eval] | \n
sculpt.symmetrize, sculpt.mesh_filter, paint.mask_flood_fill, sculpt.mask_filter, sculpt.face_sets_create, sculpt.face_sets_init, object.voxel_remesh in Sculpt Mode. Poll fails: sculpt.brush_stroke, sculpt.set_pivot_position, sculpt.detail_flood_fill, trim gestures. Work: paint_mask_extract, brush.asset_activate, Edit Mode mesh.symmetrize, quadriflow_remesh, multires ops.import openvdb): FloatGrid.copyFromArray + convertToQuads mesh the Clay.size is a diameter; Draw Sharp defaults to SUBTRACT. sculpt_tool is sculpt_brush_type.shade_smooth()), keeps attributes (mask included), drops shape keys.np.ptp(a), not a.ptp().references/procedures.md: tested code for every stage (Clay recipe, planes, form check, hair, lids, expression, final render, crash matrix, brush table, GUI recipe); load before writing any sculpt script.references/expert-notes.md: principles by expert with timestamps; load when designing a character or choosing methods.references/critique.md: stage rubric with blockers; load at every gate.references/sources.md: the 27 source videos with best timestamps.tests/code/blender-sculpting/stylized_head_blockout.py (13 s, renders in stylized_head/stage_N/); comparison: tests/code/blender-sculpting/compare/compare_sheet.png.