OtakuSolutions API Reference

This document helps you understand the Hierarchy of a BipedPlus Build result, and know where to attach customizations (capes, bracelets, etc.).

Hierarchy View is the foundation. Layer View is for organization and visibility — not the basis of rigging.

1. Why This Document

BipedPlus quickly creates the structure via Auto Rigging.
But every studio has different naming, props, and additional controllers.
Understanding the structure reveals where to customize.

2. Four Key Groups After Build

Scene
├── Grp_Mod          (Modeling Group)    ← Original mesh
├── Grp_Sys          (System Group)      ← Helpers / INFO that just need to exist in scene
├── Grp_RigModule    (Rig Module Group)  ← Arm/Leg/Head modules + Space
└── Root / Skin tree (Skin Bones)        ← Bones for engine export

Group	Role	What to do
Modeling (`Grp_Mod`)	Character mesh	Place all mesh here
System (`Grp_Sys`)	Nodes that just need to exist in scene	INFO, helpers, system nodes — animators must not touch
Rig Module (`Grp_RigModule`)	Arm/leg/head modules + Space	Main area for customization
Skin Bones	Final bones for engine export	Skinning and export reference

3. Two Spaces Inside RigModule

Group	Meaning	Used by
`Grp_Admin_Space`	BipedPlus internal calculation space	Rarely touched in normal work
`Grp_Custom_Space`	Spaces aligned to final bone positions	Where to place capes, bracelets, props

What is a Space? A group that follows a specific node's position, rotation, and scale.

Practical Example — Create Space by Selection

Select the target bone (e.g., Skin_Hand)
Run Edit_Utils → Create Space by Selection
Move the created Space into Grp_Custom_Space
Place bracelets, extra bones, or controllers under that Space

4. Customization Rules

Type	Content
✅ Allowed	Modeling → modeling group, create Space, place custom nodes, add control Ctrl
❌ Do not touch	INFO node (stores rigging data), Admin Space branches (internal calculation)

Why Use Parent Skin Bone Instead of Seg Bone

	Example	Recommended
Parent Skin bone	`Skin_Spine1`	✅ — basis for Space and custom
Seg bone	`Skin_Spine1_Seg`	❌ — may be affected by Stretch scale

5. Checklist

[ ] Can identify the 4 major groups in Hierarchy View
[ ] All modeling goes into the modeling group only
[ ] Customs go under Grp_Custom_Space + target bone Space
[ ] Don't stop at Skin Parent — also create a control Ctrl
[ ] INFO node is never touched
[ ] Do not judge structure from Layer view alone