cloth-sim

Cloth Sim

Garment blockout → sim → art-direct → bake. Stable pins. Engine-friendly caches/shape keys.

When to Use

• Dresses, capes, coats, flags, banners
• Character clothing that needs drape
• Baking sim to shape keys or Alembic/USD caches
• Pre-roll settling before animation export

Workflow

Garment mesh (quad-friendly) → Vertex groups (pin/collide)
  → Cloth modifier settings → Collision objects
  → Pre-roll settle → Sim pass → Art-direct fixes
  → Bake shape keys / cache → Cleanup → Export

Mesh Prep

• Quads preferred; even density on deforming areas
• Avoid long skinny triangles on folds
• Apply scale before sim
• Separate garment from body collider

Vertex Groups

Group	Purpose
PIN_Cloth	Anchors (waist, shoulders, collar)
COL_Ignore	Optional non-colliding regions
STIFF_High	Belts, seams that should resist stretch

Settings Starters

Look	Quality	Speed	Bending
Soft dress	8–12	1.0	Low
Stiff coat	5–8	1.0	Higher
Flag/cape	8–10	1.0–1.5	Low–mid

Tune mass and air viscosity for scale. Always run a settle pre-roll.

Bake Targets

Target	Use
Shape keys	Game poses / few frames
Alembic/USD	Cinematic caches
Armature weights	If converting to deform-only

Constraints

MUST DO

• Apply scale; define pin groups before long sims
• Collide against simplified body capsule/mesh
• Art-direct after sim (sculpt/corrective keys)

MUST NOT DO

• Sim hero cloth on ultra-dense sculpt meshes
• Skip pre-roll (starts mid-air / exploding)
• Export raw unstable caches

Reference Guide

Topic	Reference	Load When
Cloth Settings Presets	references/cloth-settings-presets.md	When needed
Pin And Collide	references/pin-and-collide.md	When needed
Bake Targets	references/bake-targets.md	When needed