Sculpting Anatomy

sculpting-anatomy

Purpose

Give every body (human, stylized, quadruped, avian, insect, aquatic, limbless, invented) structural logic and then sculpt it through the three-form hierarchy. Stylized art still needs simplified anatomy — caricature is anatomy with exaggeration.

Scope

D21 Anatomy [SIT], D22 Sculpting [SIT], Depth 16 libraries, Depth 30 brush/workflow masterclass. Retopo is modeling.

Activation Conditions

• User asks about proportions, muscles, joint ranges, sculpting, brushes, dyntopo, multires, alphas, face sets
• Creature/human needs structural logic
• Use sculpting-anatomy

Non-Activation Conditions

• Building the animation cage (→ modeling retopo)
• Texture/pore maps as lookdev (pores may be sculpted then baked — bake is lookdev)
• Design silhouette still unlocked (→ character-design)

Instructions

1. Pull numbers from Depth 16 before sculpting: human table, body-type spectra, stylized archetypes, head/face systems, joint ranges, muscle forms, quadruped/avian/insect/aquatic/limbless, invented toolkit.
2. Landmarks first (visible bones): ASIS, greater trochanter, olecranon, acromion, zygomatic, mastoid, etc.
3. Sculpt three-form hierarchy:
   1. Primary forms — big masses (gesture, proportion). Gate.
   2. Secondary — muscles, pads, folds. Gate.
   3. Tertiary — pores, wrinkles, scales. Only after primary/secondary approved.
4. Topology strategy: dyntopo for exploration, voxel remesh for even density, multires for detail on a locked base.
5. Region order (head example): skull mass → brow ridge → zygomatic → jaw → sockets → nose → lips → ears → secondary → tertiary.
6. Detail transfer: bake path is lookdev (D28); keep a high-poly archive.
7. Gate: high-poly approved → retopology (modeling).

Procedures

Invented creature toolkit (16.12)

Combine locomotion class + mass + joint scheme from existing libraries. Do not invent physics. Attach real joint ranges, then exaggerate.

Brush encyclopedia

Use Depth 30: Clay/Clay Strips for mass, Crease for lines, Smooth as a partner not a crutch, Grab for proportions, Inflate/Blob carefully, Mask + Face Sets for regions. F size, Shift-F strength, Ctrl invert, Shift smooth.

Time budgets

Primary 40%, secondary 40%, tertiary 20%. Most failed sculpts spent the budget on pores.

Decision Logic

• Realistic film human → anatomy mandatory.
• Stylized → simplified anatomy still mandatory.
• Skip sculpt for hard-surface-only assets.
• If proportion is wrong, Grab at primary — never add tertiary to hide it.

Inputs

• Sheet / creature spec / proportion target
• Style (realistic vs stylized exaggeration)

Outputs

• High-poly sculpt
• Anatomy notes (landmarks, ranges used)
• Form-gate approvals
• Hand-off to modeling for retopo
• Shared state: sculpt approved?

Tools

Sculpt Mode, dyntopo, voxel remesh, multires, custom alphas, tablet recommended. Depth 16 & 30.

Constraints

Do not animate dyntopo. Do not skip primary. Do not sculpt at final density from minute one.

Edge Cases

• Multi-species hybrid: pick a dominant locomotion skeleton, graft extras as functional or decorative.
• Stylized over-muscled hero: still obey joint ranges or the rig will break.

Failure Modes & Fixes

Dependencies

• Consumes character-design
• ⇄ modeling (retopo / cage)
• Informs rigging (joint ranges) and animation (believable motion)

Related Skills

modeling, character-design, rigging, lookdev

Delegation Rules

• Retopo/topology atlas application → modeling
• Pore maps / bake → lookdev
• Joint placement in armature → rigging (but ranges come from here)

Examples

• Adult heroic: 8.5 heads, V-torso, joint ranges from 16.5, sculpt primary masses 2 hours, secondary muscles, tertiary only on face/hands.
• Insectoid: 16.9 anatomy, chitin plates as secondary forms, legs as exoskeleton segments.

Required Knowledge / Context

• knowledge/domains/ch03-modeling.md (D21 D22)
• knowledge/depth/ch16-anatomy-proportions.md
• knowledge/depth/ch30-sculpting-depth.md

References to Shared Resources

• workflows/creature-pipeline.md
• templates/creature-spec.md