OtakuSolutions API Reference

About This Video

This is an introductory video explaining why SkinLayer Studio was built and what problems exist in the current industry — presented before the main tutorial series begins.

Problem 1 — No Weight Lock Function

3ds Max's built-in skinning has no Lock function for fixing weights.

Skin Weight Table Options

The 3ds Max Skin Weight Table offers five options: S, M, H, N, and R.

Symbol	Name	Description
S	Selection	Shown when a vertex is selected
M	Modified	Vertex is not affected by envelope changes
N	Normalize	Keeps weight sum normalized to 1
R	Rigid	Forces 100% influence from a single bone
H	Rigid Handle	Prevents handle deformation from bone movement

None of these provide a way to lock a specific bone's weight.

Real-World Consequences

Consider this scenario:

You've assigned weights to the left thigh bone, but the hip (Hip) weights have become mixed in
The hip weights were already perfectly mirrored
You need to keep the hip weights intact while isolating and transferring only the thigh weights to the right side

In Maya and other DCCs, each bone has a Lock button. Lock the bones you want to preserve, redistribute the rest, and it fills in automatically.
3ds Max has no such Lock function.

In practice, riggers had to choose between:

Turning off Normalize and manually editing each value one by one (extremely tedious)
Resetting all weights and starting over from scratch

This problem is especially common in facial rigging.
Trying to isolate cheek weights while keeping lip weights intact — without a lock function, all the work you've done is destroyed.

Problem 2 — Skinning Tools Haven't Kept Up with Game Quality

In the early 2010s, mobile games ran on small screens with simple bone structures. A single bone with weight 1 was sufficient — no twist bones needed.

But today, mobile games have reached AA or even console quality:

Arknights: Endfield
Zenless Zone Zero
Cross-device games (mobile + PC simultaneously)

Characters at this level require far more complex bone setups.
Main bones + twist bones + helper bones are now standard, and weights must be distributed with precision within each zone.

Skinning complexity has increased drastically — but 3ds Max's built-in skin tools remain unchanged.

Problems 3–5 — Additional Issues

#	Problem
3	Skinning mirror doesn't work correctly in many cases
4	Skin Wrap exists, but proper Skin Copy is not provided
5	Various bugs in the export / import pipeline

The Solution — SkinLayer Studio

OtakuSolutions always follows a problem report with a solution.

Layer-Based Weight System

SkinLayer Studio uses a layer stack approach — like Photoshop layers applied to weights.

Pelvis   [■■■■■■■■■■]  Mask: full body
Spine    [      ■■■■]  Mask: upper body
Neck     [         ■]  Mask: neck
Thigh_L  [    ■■■■  ]  Mask: left thigh
...

Each layer distributes weights only within its own mask region
Build up layers like painting in oils — each pass adds refinement
Show only active bones for the selected layer

Key Features

Per-layer weight management — edit each bone group independently
Real-time smooth brush — weight changes reflected instantly and smoothly
Mirroring — systematic, reliable support
Export / Import / Weight Copy — supported

Closing

SkinLayer Studio runs as a 3ds Max plugin, providing its own viewport while directly reading and writing the skin data inside 3ds Max.

This tool was built by OtakuSolutions for our own real production use.
Quality and direction will be continuously improved, with the goal of becoming the best skinning tool available.

Starting from the next video, we'll walk through how to actually use it.