Realistic characters and creatures (ZBrush 2026)

Expert level here means every form has a cause (skull, mass, tension, compression) before any pore exists, and every detail pass is reversible, regional and judged in renders from several views and lights. The agent works the way Kingslien and Costa do: find the upstream cause, fix it at the lowest level that holds it, and keep detail on layers or behind a stored morph target. 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-zbrush-expert (bridge, stroke engine, review loop, 2026 traps). Toolkit: scripts/zb_character.py (stroke plans, ZBrush-side wrappers via zb_character.call(...), OBJ, alpha and render checks) on the lead's toolkit.

Stance (the expert delta)

• Cause before form, in planes. Kingslien: cranial versus facial mass, then the Bridgeman masses (forehead box, flat cheek, maxilla cylinder, triangular jaw), then features sculpted through the forms around them (nostril through the alar facial juncture, eye through the nasojugal groove). "Almost everything right or wrong in this face is right or wrong back in the beginning." A region touched twice means replan (MoveBudget). His single separating lines suit synthesized strokes.
• Detail is worthless on a weak base. Costa: judge primaries blurred, from afar, upside down and under three lights from the first sketch; keep level 1 alive for likeness edits until export.
• Asymmetry lives in the big forms. FlippedNormals break symmetry in the mid-frequency pass; J Hill again in the last 25 percent (nose tip off the axis, one ear, a lip corner, one eye's scale); Lazov pushes the whole creature from a stored morph target. Creature big forms: skull mass, one orbit rim, the jaw corner, a nostril, a horn's angle. Scars and broken scales come on top, never instead.
• Skin: scale first, regions second, breakup third. J Hill sets pore scale globally for age and sex first; lids and lips stay clean; even skin between details reads as plastic. Lines lie across the compression, in short connected segments (Costa: wrinkles connect pores, perpendicular to the circular muscles). Cracks on horns and tusks go large to small in stages (Starkie).
• Scales follow the anatomy; alphas never finish a surface. Henning Sanden: generic tile, mid value 50, tested on the model at least three times while you build it, then a hand unify pass; smooth inside a scale, never across its border. Starkie: a close-up hero gets individual scales (he gives no numbers). Berger: story, then biology, then cool; reference animals blended with no seams.
• Sharp enough to survive the render. FlippedNormals: carve deeper than feels right, because SSS and soft light eat sharpness; J Hill: only the sharp detail survives in the highlights. Over finished detail ClayBuildup erases what is under it: enhance with Standard, make directional passes with Elastic.
• Folds and poses have causes. Grassetti: every fold starts at a tension point, ends in another fold or an edge, is heavier near the tension; tightness picks drop, zigzag, X or Y. Eaton: only the force chain is tense; active muscles run straight between landmarks; scapula about 30 degrees at 90 degrees of arm elevation.
• Agent limits [added]. Transfer well: palette operations, feature masks plus Deformation sliders, layers and morph targets, two-point alpha stamps, short lines, spray loops, curves-API horns. Stay weak: Costa's thin ClayBuildup layering, groom and Morph-brush feel, anything needing Ctrl or Shift held, and HD Geometry (the A key cannot be sent). Say so in the report.

Establish first

Input	Changes	Default when silent
Purpose and shot	stack, map path	film close-up still, 32-bit displacement into Maya/Arnold [added]
Driver	stack route	SDK only: regular levels, no HD; computer use: HD split
Subject and reference	canon, blend	human: A4S canon, Costa's millimeters; creature: two or three animals blended (Berger)
Age, sex, weight	pore scale, fat pads, gonial angle	adult, written down first
Pose	symmetry strategy	neutral: symmetric until the mid-frequency pass; posed: symmetry off (Eaton)
Base mesh	where detail starts	ZRemeshed quads with UVs and interior polygroups (eyes, mouth, nostrils) from scenario-zbrush-retopology-export

Workflow

0. Brief and maps. Design pyramid (Berger); rest versus rich zones (Lazov); scale flow over the anatomy (Henning). GATE: all three written down.
1. Masses (from scenario-zbrush-sculpting, or skull first here, Lazov). Head: cranial versus facial mass, then Bridgeman masses on a stroke budget (Kingslien: 16 Move strokes; C2). Creature: skull, jaw hinge, horns (C17), open and closed mouth on layers (Berger). Figure: landmarks first (Eaton). GATE: sheet with front, profile, three-quarter and below (view_facing("-Y")); head_ratio_check or scapula_check passes or the deviation is deliberate; no retouched region.
2. Face critique pass in Kingslien's order (references/critique.md). The first failing step is the fix: a separating line (C3), a masked move (C4) or plane strokes. GATE: face_report moves the right way against the previous stage.
3. Topology, stack, projection. Detail only on a clean, UV'd base. Choose the route before the first Divide (C5): SDK only, subdiv_plan(route="regular") to about 20 to 25M, micro detail in a tiled map at render; computer use, 3 to 4 regular levels (top 1 to 2M) then 3 to 4 DivideHD. Never add HD over a 6 or 7-level stack: you cannot go below the HD entry (J Hill). Reproject with zb_ops.project_all (checkpoint, morph target and top-level layer built in), eye, mouth and nostril interiors masked first; then walk every level (C19). GATE: stack_check ok; spike_report ok in every danger-zone group; points per level logged.
4. Secondary forms: folds, wrinkles, fat pads, lids, lips; Costa's thin ClayBuildup (Z 2 to 3, many short strokes), Kingslien's lines; symmetry off for the big-form mid-frequency pass. Cloth: plan folds (C13) or simulate, then sculpt (C14, C15). GATE: blurred and thumbnail renders; no form "screams".
5. Tertiary detail, one layer per frequency (layer_new, agent-side ledger). Aim first: aim_at the region, stamps inside region_on_canvas (C9). Pore or scale bed: Surface Noise (C7) or alpha stamps (C8, C9), each alpha tested on the model while built. Wrinkles across the compression (C10); cracks with crack_tree, largest first; breakup (C11); hand unify. GATE: raking close-ups; alpha_check (and dots_check if dots were used); no tiling; lids and lips clean; each layer seen at intensity 0 and 1.
6. Asymmetry pass (C12), big forms first. GATE: asymmetry_report finds at least two big-form regions broken; posed figures skip it.
7. Fur and hair (C16). Mask, preset from a file, Preview, Accept, Fast Preview PRE Vis 6 to 8. GATE: coverage render with a contrasting fill.
8. Final review and handoff (C20). Costa's eight steps under three lights, upside down, blurred; eye_report; detail_survival on the SSS render; map_request_check; versioned ZTL. GATE: scorecard passes, or open items listed.

Numbers

Item	Value	Source
Stack, SDK only	regular to about 20 to 25M (6,240 faces reach 25.5M at SDiv 7); "40 million is high"; micro detail tiled at render	J Hill; Costa
Stack, computer use	3 to 4 regular levels, top 1 to 2M, then 3 to 4 DivideHD (Costa: 1.1M top, 3 DivideHD, 70M); HD ceiling 1 billion, so 3 DivideHD over 16M is already at it	Costa; J Hill; HD doc
Reprojection	target at about 3M; Store MT and a layer at the top level; PA Blur lowered	FlippedNormals
Face block-in	under about 360k points with Sculptris Pro	Kingslien
Head canon	crown to hairline 1/6 H, then thirds of 5/6 H; eyes at 1/2 H	Anatomy For Sculptors
Portrait scale	head 229 mm, eyeball 24 mm, IPD 63 mm, eyes 3 to 10 degrees outward	Costa
Wrinkles	Standard + Alpha 39, sharpened curve; fine: Standard, Spray, Alpha 60, Z 3	Costa; J Hill
Pores	DragRect, Focal Shift -100, one size per zone; Surface Noise strength negative	Costa; J Hill
Alpha tile	plane, Smt off, about 1M polys (a 1K map), document 1024, perspective off, +50/-50 dots taller than any detail, MidValue 50; tested at 11, 26, 41 minutes	Henning
Folds	Standard Z 25 valleys, Clay Z 80 ridges, big Move for sag, SDiv 2 to 4 first	Grassetti (frames)
Cloth	Gravity 1 to 2.5; iterations 100 to 1000; Firmness 1 to 2 silky, 5 to 6 leather; collision about 1024; Extract Thick 0.01 cloth, 0.03 leather	Pavlovich; Maxon docs
Fur	Max Fibers 11 (thousands), Segments 6, PRE Vis 6 to 8, Profile 1	Pablo; FiberMesh docs
Horns	detail straight, radial counts 8, 5, 3, then bend; decimate a copy to 20 % (arrays 5 % then 1 %); curve Res 10, Imbed 0	Pablo

Quality gates

• Measured: stack_check; points per level and layer count; spike_report per polygroup at every level; head_ratio_check within 5 percent of H [added]; face_report deltas; mirror_deviation and asymmetry_report; alpha_check, dots_check; fold free_endpoints = 0, evenness > 0; area drift under 5 percent after a sim [added]; eye_report; detail_survival ratio at least 0.5 [added]; map_request_check; volume before and after every stroke batch.
• Seen: zb_review.review sheets in MatCap Gray (front, profile, three-quarter, below, back), raking close-ups per region and per danger zone after projection, blurred, thumbnail, upside_down, and the three-light SSS render (highlights keep the sharp detail). references/critique.md says what to look for.

Common mistakes

Mistake	Looks like	Fix
Features on an undivided egg	no facial plane in profile	cranial versus facial mass, Bridgeman masses (C2)
Eye centered in the orbit	straight rim, lumps under the eye	eye high, margin hooked into the orbit, check from below (C3)
HD on a deep regular stack	6 or 7 regular levels then HD; no smoothing room; 1 billion faces	route chosen first, stack_check (C5)
Projecting without nets	spikes in lids, lips, nostrils, fingers; hard lines in the displacement	project_all nets, interiors masked, level walk; morph_repair, never smooth (C19)
Symmetry broken only in details	scars on a mirrored skull	move the big forms (C12)
Uniform detail	plastic, noisy, no rest	region map; lids and lips clean; beat-up at three sizes
Alpha built blind	soft, tiled, bordered on the model	test on the model while building; dots taller than any detail; hand unify (C8)
ClayBuildup over finished pores	detail erased	Standard to enhance, Elastic for direction
Micro detail too soft	gone in the SSS render	carve deeper; detail_survival
One long wrinkle line	drawn, not skin	short connected segments across the compression (C10)
Lone or even folds	dangling ends, ladder of copies	termination and unevenness rules (C13)
Sim stretch or ghost collider	long polygons at contacts; cloth hugging nothing	more iterations or less gravity; Recalc after visibility changes
Fibers lost	groom vanished, FiberUV grayed	neutral settings before a groom; groom first, Divide last

Handoffs

• Receives from scenario-zbrush-sculpting: a versioned ZTL with the primary forms, polygroups per region, stats() and the last sheet. From scenario-zbrush-retopology-export: the clean quad base with UVs (UDIMs), interior polygroups for eyes, mouth and nostrils, and the projected stack (rx.project_stack).
• Delivers to scenario-zbrush-retopology-export: the detailed ZTL with level 1 intact, eyes as separate SubTools, layers baked or the ledger, a morph target at the export level, and a map request that passes map_request_check (Adaptive identical across maps, SubDiv below the top, Mid equal to the renderer's zero, UDIM tile names with a dot, Merge Maps off with EXR; Costa's film values in references/procedures.md C20). UVs relaid outside ZBrush come back by Store MT, Switch, Import at the export level, no Divide, Switch MT on (Costa). To scenario-zbrush-paint-render: the same ZTL, region polygroups, grayscale approval renders and the three-light SSS request.
• Related: scenario-zbrush-stylized, scenario-zbrush-pose-print, scenario-maya-groom (XGen).

ZBrush 2026 notes

• Not scriptable: HD entry (A key; press_key "does not work"), layer names (the macros rename through ZFileUtils), mask painting, Shift-smoothing, the NoiseMaker window (set once by computer use, save a .ZNM).
• Brush:Dam_Standard does not resolve on 2026.2.1: select brushes through zb_ops.select_brush, run brush_check once per session. Orb_Cracks, RK_ and Antro_ brushes do not ship: Dam_Standard, Slash3, ClayBuildup, TrimAdaptive stand in.
• Since 2026.1 custom alphas and brushes live in the Asset Directory (alpha_library_dir()). NoiseMaker 2.0 (2026.0) rotates a tiling alpha to follow each region's flow. Redshift inside ZBrush runs the SSS check; Substance Bridge (2026.2) is the Painter route.
• Decimate a duplicate, never the master (rx.decimate_copy); a scripted pre-process may end the calling script [verify].
• Unconfirmed: layer intensity path, NoiseMaker blocking, scripted Run Simulation stop (live_c01, c03, c05).

References

• references/expert-notes.md: principles by expert with timestamps, conflicts with their deciding condition. Load when planning a stage.
• references/procedures.md: bridge procedures C1 to C20, full code, live tests. Load before writing bridge code.
• references/critique.md: Kingslien's face checklist, Costa's evaluation, skin, creature, projection, cloth and fur rubrics. Load at every gate.
• references/gui-paths.md: palettes, hotkeys, brushes, settings for a computer-use agent.
• references/sources.md: sources, credentials, URLs, best timestamps, revision log.