# EP07 — Fingers (Layer Group)

https://youtu.be/z9Ex-iERxeU?si=JwtY-O2_U96Sgzd6

## 1. Why Fingers?

- Fingers have dense bones requiring weights and masks for every joint, making them time-consuming.
- **Layer Group** + Mask copy/paste lets you **quickly repeat a consistent pattern**.

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## 2. Layer Group Concept

| Regular Layer | Layer Group |
|---------------|-------------|
| Layers in the full stack influence each other up and down | Inner layers blend only among themselves; the combined result contributes to the outer stack |
| — | Like a folder in Photoshop — merged inside the folder before being added to the outer stack |

- Create: **Right-click layer → Create Layer Group**.
- **Maximum 2 levels of nesting** recommended — deeper nesting is inefficient to compute and manage.

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## 3. Finger 1 (Index) — Group Demo

1. **Finger1** (or `Finger1_Seg`) layer — Weight and Mask set to full 1.0.
2. **Right-click layer → Create Layer Group**.
3. Paint the **Group layer's own Mask** onto the **loop ring where the joint bends** — this Mask limits the group's influence range.
4. Use **Select Bone** to bend the finger → the individual Finger layer has weight 1.0 (full body), but the **Group Mask** only passes through the joint ring, precisely constraining where the bend occurs.

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## 4. Fingers 2–4 Fast Setup

1. Add layers: Finger2, Finger3, Finger4 — disable inactive layers and organize order.
2. Flood 1.0 on each Seg bone + **knuckle Mask** (leave extra room toward the palm for the pinky).
3. Confirm coverage with **Shader ▾ Gray Shaded** (key **5**).

### Mask Copy / Paste
- From a well-done mask layer: **Copy Mask**.
- On another finger layer → **Paste → Replace Mask**.
- Correct the gaps between fingers with **Add** mode.

### F Key — Frame Selection
- Select vertices, then press **F** — **frames the camera** to the selection (finger close-up).

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## 5. Mirror · Debugging

- **Mirror** (Weight + Mask + group internals).
- If something looks off: **deactivate all layers**, then turn them on one at a time to find overlaps.
- If the pinky pops: shrink the Group Mask, then in the Influence panel **right-click Root → Cut Weight**, then Add to the correct finger bone.

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## 6. Hand (Wrist)

- Move below the Finger group in the stack order.
- **Hand_Seg** layer — Mask from wrist to palm.
- If weights are too strong: Vertex Multiply down + Smooth.
- Mirror.

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## 7. Thumb (Finger0)

- Biped: **Finger0** — same process as other fingers, just a different rig name.
- Keep the Mask narrow to minimize overlap with the palm.

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## 8. Wrap-Up

- **Mirror** each Finger + Mask.
- Center area (thumb, palm) may need **manual** correction.
- **Full-body dummy** work complete — next up: **clothing** (ep08 onward).
- Layer Group uses the same pattern in ep09–10 for the skirt.