VRM - Extending glTF for Portable Humanoid Avatars

What is “VRM” ?

A glTF based, platform independent 3D humanoid avatar specification

and file format.

Designed to make humanoid avatars portable,easy to handle for various applications.

VisionCreate Own Multi-use

• Virtual Beings are truly living in the internet world today. • VRM believes that world is better place if you can bring your avatar to

wherever you want to go.

VRM Applications

Problem

Blend shape(morph)

UV offset

Material switch

Eye bone

Blend shape(morph)

Facial animation Eye expressions

A stance T stance

Default stance

Model scale

Coordinate system

etc, etc…

UV offset

Humanoid Rig

Local rotation

Problem

• No standards for character models, rigs and controls.

• Hard to support various difference characters for Application developers.

HumanoidRig

Our Solution

VRM creates intermediate layer and constraints that makes application capable to control avatars in uniform manner.

Eye control

Application

VRMLookAtHead

VRM API

Blend shapeFacial(Emotion)

Eye bone

Data constraints requirement(Scale, data type, local rotation, stance …)

VRM Structure

Bare glTF 2.0 (.glb)

Base technology

VRM extension for Humanoid avatar(Humanoid bone structure, Secondary Animation, Licenses …)

VRM extension

Cel shading (NPR) material definitionMaterial extension

• Reference implementation to handle VRM files in Unity.

• MIT License• Supporting runtime avatar import• Other implementations are also available by

community.• Three.js• Babylon.js• Unreal Engine 4 (VRM4U)

Reference Implementation (UniVRM)

VRM/Humanoid• Humanoid bone structure defined as glTF

extension

glTF extension

• To support Anime-like styles, expressions are defined as changes of blend shapes (morph)and materials respect to vowels and preset expressions (angry, fun, etc)

• These preset patterns can be extended

VRM/EmotionglTF extension

• Application controls the avatar through VRM API by commanding “expressions” instead of directly controlling bones or blend shapes.

• This middle layer let applications handles different styles of avatars in uniform manner.

Emotion“Joy”

Application

VRMBlendShapeProxy

VRM API

VRM/EmotionglTF extension

• Simple secondary animation system• Intended to be used for (non-realistic) hairs and

cloths• Open algorithms, intuitive parameters.• Put weight in simplicity to ensure

portability rather than being feature rich.

VRM/SpringBoneglTF extension

• Anime look material definition• Provided as part of default

implementation. Also ported to WebGL.

VRM/MToonglTF extension

• EULA/License of distributing avatars can be defined and included• Avatar-minded Permissions

• Permit/Prohibit violent activities when playing with this avatar? • Permit/Prohibit to play original personality?

VRM/LicenseglTF extension

Avatar data must be transmitted to render world

VRM/LicenseglTF extension

• Avatar data must be given to others - doesn’t means you can own those avatars.

• Comprehensive, avatar-specific licenses and permissions are important to protect your appearance in virtual world.

VRM/HumanoidglTF extension

NHK STRLNintendo

Members

Observers

SIGGRAPH ASIA 2019 Real-Time Live!

• 20th Nov 4:00pm Real-Time Live!

Thank you!

vrmc-pr@vrm-consortium.org

mailto:vrmc-pr@vrm-consortium.org