ZBrush posing and 3D print

Expert level means a pose that stands and reads, transferred onto every SubTool without losing a level, and print parts whose size, walls, fits and cavities were measured in millimeters on the exported files. The stance: turn every decision into a number the agent can check (scale, point order, joint angles, walls, gaps), keep the pose reversible, use strokes only for cleanup. 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).

Stance (the expert delta)

• Gaboury: scale is the first decision. SubTool number one is a box at the client's size; nothing may clip out of it, and the whole tool resizes in one step because sizes change late (6 in with 15 points of articulation became 4 in with 8). Agent form: brief_box, zb_print.envelope, set_export_scale(target_mm).
• Munoz Gomez: pose at the lowest level, several SubTools through Transpose Master, the pose on a 3D Layer. Plates and carried props (weapon, shield, staff) stay IN the TPose mesh as rigid pieces (Auto Groups, one group per loose piece, masked whole); Move Topological clears intersections. Plouffe forbids deforming primitives, not moving them rigidly: never pull a carried prop out and re-place it with one rotation.
• Maxon doc: two things destroy a transfer: a partially hidden SubTool (Vertex Mismatch) and Gizmo 3D deformers on the TPose mesh (they reorder points; SubTools die on TPose>SubT). Pavlovich: "The order of the vertices is very important." Start from a clean project, save the ZPR while a TPose mesh exists (the Transpose Master data lives there).
• Plouffe: parts that bend together need the same polygon size at level 1 (mask blur spreads per polygon). Re-place bolts and discs after bending. Spend detail only where the final size and viewing distance show it.
• Pavlovich: DynaMesh without levels = Proxy Pose plus a ZSphere rig. Location beats size, helpers hold volume, rotate only.
• Gaboury: never hollow the 9M sculpt. Shell a light DynaMesh copy (128 was enough for a 9 in car), keep its inner wall, Polish it, subtract it from the untouched detailed part in Live Boolean. Create Shell Thickness is not millimeters: measure.
• Bennett (Hasbro): 1 mm minimum wall (0.85 mm was flagged), 0.5 mm edges, 0.12 mm fit offset for Formlabs parts; thin walls are thickened from the inside so the outside does not change.
• Gaboury: decimate by eye (about 1M per mesh is plenty; 10k to 20k triangles can still print); masks on the detail that matters (face, hands) steer Decimation Master; pre-process again after any edit; vent every cup on SLA.

Establish first

Input	Why it changes the plan	Default when the brief is silent
Process: resin (SLA, MSLA), FDM, molded or cast	walls, clearance, hollowing, shrink (Hasbro sculpts PVC at 104 %); molds add Hasbro's rules: touching fingers lock the mold, Group Front shows the parting line, Draw Draft Analysis shows draft	resin, direct print
Size: ratio and real height, envelope W x H x D, base included or not	export scale, brief box, feature floor	1/6 = standing height / 6 (1,800 mm gives 300 mm), measured on the rest pose
Printer volume, slicer caps	splits (Gaboury split a car for the Form 2 bed); polycount or file caps (his example: 50 MB)	ask; report each part's size
Parts: one piece or kit, glued or pegged	cuts and keys (Carratala plans cuts while sculpting)	natural breaks (collar, belt, cuffs, weapon at the hand), two keys per glued joint [added]
Pose source; alternate poses	route and layers	one layer per pose
Deliverable	STL has no units; 3MF declares them	STL and 3MF per part in mm, JSON report

Posing without a mouse

The artists' default (Ctrl+click a polygroup, drag a Gizmo ring) is a canvas gesture. The SDK cannot read mask data, and press_key is documented but marked "Does not work, hidden for now" in the installed 2026 stub (with canvas_click it is reported unreliable, Maxon forum). Routes by determinism:

Route	When	How	Status
A. Numeric external rig (Munoz Gomez's Blender route, made exact)	humanoids, extreme or many poses	TPoseMesh, export_tpose, loose_pieces weighted rigidly to one bone each, scenario-blender-rigging poses by angle and returns the same order, import_pose, TPose>SubT	deterministic; guards tested offline
B. ZSphere rig by code	in ZBrush, organic, or DynaMesh via Proxy Pose	joints from polygroup borders, zs_build, forward kinematics zs_pose	FK tested; bound mesh following API edits [verify live_p02]
C. Whole-SubTool rigid moves	a base, a stand, a prop added after posing	rotate_subtool_matrix (X, Y, Z) plus translate_subtool, the carrier's whole transform, corrected from exports	math tested; signs [verify live_p03, p08]
D. Mask plus Gizmo or action line	cleanup by a computer-use agent or a human	Ctrl+click group, Alt pivot, drag	weak for this agent

Weak without a human: gesture design, Plouffe's hand-painted gradient masks, large fold redesign. Seam smoothing and Move Topological have agent forms in procedures.md P6, still [verify].

Workflow

zb_pose.call("name", ...) runs inside ZBrush; zb_print runs on exported OBJs; full code in references/procedures.md.

0. Intake. Versioned ZTL, inventory(), target and envelope in mm. GATE: every SubTool named, unique, with points and levels.
1. Scale. set_export_scale, export_parts, check_scale, then brief_box (hidden while exporting). GATE: height within 0.5 % [added], one export scale on every part (a part appended from another ZTool arrives at another scale), envelope ok, named dimensions checked with caliper.
2. Pose prep. clean_project (ZTL saved, default project, Load Tool); polygroup every segment, plates and props left as loose pieces; preflight_tpose. GATE: preflight ok, density spread under 2x [added]. No levels: scenario-zbrush-retopology-export or Proxy Pose.
3. Pose. tpose_mesh(layer=True, groups=True) with props and plates visible, export_tpose (the order reference), save_project; route A or B, center first, parents before children, rotations only; no Gizmo deformers. GATE: rigid_pieces ok, follows puts each carried prop where its carrier took it (0.5 mm [added]), piece_interference empty or listed for P6, tpose_to_subtools(expected, rest_obj) passes its order guard and point counts, rigid_delta within 2 degrees of the plan [added], balance stands or a base is planned; review sheet: silhouette and weight read (Plouffe: an unstable pose "destroys the entire work").
4. Fix deformation. New layer at the top level. Seam first while the rest is protected (Munoz Gomez smooths and moves before clearing the mask); then volumes and folds re-sculpted for the new pose (tension from the stretched joint, compression on the inner bend [added]); re-place primitives; Move Topological on pieces; pose-specific detail on a pose-only layer, because layers blend linearly. GATE: stretch_report near the rest pose, piece_interference ok, Polyframe tiles.
5. Breakdown. Parts at natural breaks; merge what prints as one (Live Boolean union or DynaMesh on light copies: Hasbro engineers on decimated meshes). Molded: loops, parting line, draft. GATE: each part closed, fits the build volume.
6. Hollow when asked. hollow_copy (insert inside, DynaMesh about 128, Create Shell), keep_inner_shell, Live Boolean: detailed part start, inner shell, drain and vents subtract; thin ends stay solid. Too thin: move the cutter inward, never the outside. GATE: thickness p01 at the wall target, no sealed cavity for resin, outer_drift ok, vents at cups.
7. Cut and key. Cutter QCube in Live Boolean or a polygroup split then Close Holes [added]; plan_keys; socket = peg grown by 2 x clearance. GATE: clearance median at target, no interference; one key pair test-printed before the kit (Gaboury).
8. Decimate. Unique names; per-SubTool budgets, masks before Pre-process (mask="cavity" [added]), pre-process after any edit. GATE: faces within budget, deviation p99 under the printer's XY resolution [added], close-ups before and after.
9. Deliver. STL and 3MF per part in mm, print_report(..., envelope_mm=...), a review tile at real size (detail under the process floor is backfilled, fused or left to paint: Hasbro). GATE: print_report["ok"], every "to look at" item looked at, unit stated.

Numbers

Item	Value	Source
Minimum wall	1 mm; 0.85 flagged	Hasbro, PVC and Formlabs copies
Edges after trimming	0.5 mm; about 0.2 mm floats away	Hasbro
Fit offset	0.12 mm (Formlabs); Inflate 2 gave it in his ZTool	Hasbro, calibrate per ZTool
Shell copy	DynaMesh 64 too low, 128 enough (9 in car); Thickness 4 then 6	Gaboury
From Thickness	Min 1, Max 5 once scaled to mm	Maxon doc
Decimation	about 1M per mesh; 2.7M to 545k at 20 % unchanged; 8k faceted	Gaboury
Decimation quality	40 to 100 % near identical, 2 to 40 % visible	Maxon doc
Scale with shrink	height / 12 + 4 % for a 6 in PVC figure	Hasbro
Proxy Pose skin	Adaptive Skin Density 1, DynaMesh Resolution 0	Pavlovich

Quality gates

• Measured (zb_print on OBJs in mm): watertight, volume, thin-wall share (0.2 % of samples [added]), sealed cavities, floating shells, height, envelope, one export scale, build volume, clearance, balance, faces, outer drift. Pose: point order, rigid_pieces, follows, piece_interference, rigid_delta, stretch_report.
• Visual (scenario-zbrush-expert zb_review.review, MatCap Gray, five views): gesture and balance; joints with Polyframe; primitives round; the grip closed around the handle; the brief box shown once; From Thickness on a copy; every listed spot; decimated close-ups. Judge with references/critique.md.

Common mistakes

Mistake	What it looks like	Fix
Top-level pose, rough mask, mask cleared too early	stretched, overlapping polygons	lowest level, blurred mask, Smooth and Move the seam before clearing (Munoz Gomez)
Carried prop pulled out of the TPose mesh, turned by one angle afterwards	a sword beside a raised, bent hand; interference 0 still passes	keep it in the TPose mesh as a rigid piece; else the carrier's whole transform, gate follows
Partly hidden SubTool at TPoseMesh	Vertex Mismatch	preflight_tpose (ShowPt on all)
Gizmo deformer on the TPose mesh	destroyed SubTools; a point count check misses a reorder	rotations or rigs; the order guard refuses the transfer
Session closed with a TPose mesh, no ZPR	no way back to the SubTools	save_project right after TPoseMesh
Neutral-pose detail shown on the pose	soft, stretched detail at bends	refine on a pose-only layer (linear blend)
Create Shell numbers read as mm; insert touching the surface	wrong walls; one joined piece	measure thickness; insert inside, drain as a cutter
Wall thickened from outside	the sculpt drifts	move the cutter inward, check outer_drift
Mask or edit after Pre-process	decimation ignores it	pre-process again (the wrapper always does)
No clearance on keys	"20 discs to sand before noon" (Hasbro)	0.12 mm offset, measured, test print
STL without a unit	150 mm printed as 150 in	say mm, or ship 3MF

Handoffs

• Receives from scenario-zbrush-sculpting, scenario-zbrush-character-creature, scenario-zbrush-stylized or scenario-zbrush-hard-surface: a versioned ZTL with named SubTools, levels (or a DynaMesh for Proxy Pose), polygroups per part, the last review sheet; from scenario-zbrush-retopology-export, a projected stack when a sculpt had no levels.
• Sends to scenario-blender-rigging or scenario-maya-expert: the TPose OBJ and a plan (joints, angles, rigid pieces per bone), expecting the same vertex order back.
• Delivers posed sculpts (layers, ZTL, ZPR, sheets) to scenario-zbrush-paint-render; print packages (STL and 3MF in mm, report, sheets, part and key list) to the user or the printer.

ZBrush 2026 notes

• Proxy Pose (2023.1) is in Tool > Geometry. Transpose Master still ships ("inactive after a file save" fixed in 2025.2); its data lives in the ZPR. The doc's clean project, DefaultCube.ZPR, is not in the 2026.2.1 install: Lightbox/Projects/DefaultProject.ZPR is used [verify].
• 3D Print Hub has Export to 3MF (errors fixed in 2026.2.1). Update Size Ratios and Scale Master Set Scene Scale open dialogs: use the export scale route.
• From Thickness (2026.2.1 labels Min Thickness, Max Thickness, Ball or Ray) asks "Too many polygons... proceed?" above Max Thickness Polygons; that note stalls the bridge, so from_thickness refuses first.
• Live Boolean drops UVs, creases, 3D layers and masks on the result: boolean the print copy. Decimation Master and Transpose Master are ZScript plugins: check that control returns (live_p01, p07). Cmd+W quits ZBrush on macOS.

References

• references/procedures.md: bridge procedures with full code (scale and brief box, clean project, Transpose Master, three rig routes, fixes, hollow chain, keys, masked decimation, delivery). Load before driving ZBrush.
• references/expert-notes.md: principles by expert with timestamps and deciding conditions. Load when planning a pose or a kit.
• references/critique.md: the rubric for pose, deformation and print parts. Load at every gate.
• references/gui-paths.md: palettes, buttons, hotkeys for a computer-use agent or a human.
• references/sources.md: sources, credentials, timestamps, revisions.
• scripts/zb_pose.py (inside ZBrush) and scripts/zb_print.py (agent side, numpy): offline tests in tests/code/zbrush-pose-print/; live tests live_p01 to live_p08 not yet run in ZBrush.