03. Masking System

Purpose

When an outfit is equipped on a character:

• It should naturally hide the character's body mesh, and
• Enable proper layer combinations without visual conflicts.

To achieve this, you must correctly understand and apply Drawing Regions, Covering Regions, and Body Regions.

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Why the Masking System Is Needed

• A single outfit works fine by itself,
• But when combined with other outfits, or
• Overlaps the body mesh,

→ Visual issues like mesh clipping or intersection may occur.

To prevent this:

• Define which areas of your outfit should be masked (Drawing Regions)
• Specify which lower-layer outfit parts should be hidden (Covering Regions)
• Hide specific parts of the character’s body (Body Regions)

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Masking System Overview

System Type	Description	How to Apply
Drawing Regions	Areas of the outfit to be masked	Place UVs in designated regions on UV Channel 2
Covering Regions	Parts of lower-layer outfits to hide	Assign Covering Region IDs
Body Regions	Body parts to hide when equipped	Assign Body Region IDs

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1. Drawing Regions

- Description

• Set mask regions using UV Channel 2.
• Place UV shells into the designated region areas.

- UV Channel 2 Workflow

1. Create UV Channel 2
2. Move UV shells to the correct Region ID areas
3. Use guides to avoid overlap between different regions

- Example Region IDs

Region ID	Description
Chest	Chest area
BellyUpper	Upper abdomen
LeftArmUpper	Left upper arm

- UV Channel 2 Region Guide

- Upper Layer Masking Region Guide

- Lower Layer Masking Region Guide

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2. Covering Regions

- Description

• Use this when your outfit should hide another outfit in a lower layer.
• Example: If a long top covers the waist of pants, set PantsWaist as a Covering Region.
  • The pants must also have PantsWaist in their Drawing Regions, properly set in UV2.

- Covering Region Workflow

1. Add individual or group IDs in the "Covering Regions" field

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3. Body Regions

- Description

• Defines which parts of the character’s body mesh should be hidden when wearing the outfit.
• Used to prevent body parts from poking through shirts, pants, shoes, etc.

- Body Masking Region Guide

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Full ID List (Summary)

Drawing / Covering Regions (Clothing Parts)	Body Regions (Body Parts)
LeftShoulder, RightShoulder	ChestUpper, BackUpper
Chest, Back, BellyUpper	LeftArmUpper, LeftElbow
LeftArmUpper, RightArmUpper	BellyUpper, BellyLower
LeftThigh, RightThigh	WaistBack, Pelvis
LeftShin, RightShin	LeftShin, RightShin
LeftFoot, RightFoot	LeftFoot, RightFoot
etc.	etc.

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Group ID System

Group IDs allow bundling multiple Region IDs into a single convenient setting.

Group ID Name	Example Included Regions
UpperBodyClosed	Chest, BellyUpper, Back, LeftArmUpper, RightArmUpper
BottomMid	BellyLower, Buttocks, LeftThigh, RightThigh
ArmsAll	LeftArmUpper, LeftArmLower, RightArmUpper, RightArmLower

• Beginners can use Group IDs for faster setup
• Advanced users may add individual IDs for more control

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Common Mistakes & Fixes

Mistake	Cause	Solution
UV2 not set	UV Channel 2 not included	Make sure UV2 is exported
My outfit isn’t masked	- Incorrect UV2 setup - Missing Drawing Region ID - Missing matching Covering Region ID	- Fix UV2 - Add Region IDs
Lower outfit not masked	- Missing Covering Region ID - No matching Drawing Region on lower outfit	Fix Covering Region ID
Body pokes through outfit	Body Region not set	Add the correct Body Region ID

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**Chapter Summary

Checklist	Done
UV Channel 2 created and placed	✅
Drawing Regions set	✅
Covering Regions set	✅
Body Regions set	✅
Group ID used if needed	✅