collada/gltf bof - khronos group · collada/gltf bof siggraph 2013 ... smith micro software july 24...

© Copyright Khronos Group 2013 -

COLLADA/glTF BOF

SIGGRAPH 2013


3D Needs a Transmission Format! • Compression and streaming of 3D assets becoming essential

- Mobile and connected devices need access to increasingly large asset databases

• 3D is the last media type to define a compressed format

- 3D is more complex – diverse asset types and use cases

• Needs to be royalty-free

- Avoid an ‘internet video codec war’ scenario

• Eventually enable hardware implementations of successful codecs

- High-performance and low power – but pragmatic adoption strategy is key

Audio Video Images 3D

MP3 H.264 JPEG ? !

An effective and widely adopted codec ignites previously

unimagined opportunities for a media type


glTF Goals • Binary file format for efficient transmission for 3D assets

- Reduce network bandwidth and minimize client processing overhead

• Run-time neutral - DO NOT IMPLY OR MANDATE ANY RUN-TIME BEHAVIOR

- Can be used by any app or run-time – usually WebGL accelerated

• Scalable to handle compression and streaming

- Though baseline format does not include compression

• ‘Direct load efficiency’ for WebGL

- Little or NO processing to drop glTF data into WebGL client

• Carry conditioned data from any authoring format

- Prototyping and optimizing efficient handling of COLLADA assets

A standards-based

content pipeline for

rich native and Web 3D

applications Playback Authoring


COLLADA and glTF Ecosystem

Tool Interop

Three.js glTF Importer. Rest3D initiative

COLLADA2GLTF

Translator

OpenCOLLADA

Importer/Exporter

and COLLADA

Conformance Tests

On GitHUB

Pervasive WebGL deployment

Other

authoring

formats

Web-based Tools


Our Speakers Today! • Update on the COLLADA and glTF Ecosystem

- Neil Trevett, Khronos President, VP Mobile Content NVIDIA

• OpenCOLLADA update

- Uli Klumpp, Smith Micro

• COLLADA and JavaFX 3D

- John Yoon, Oracle

• COLLADA and AutomationML

- Fabrice Robinet, COLLADA Working Group Chair

• glTF


• Integrating glTF and Three.js


• glTF in Cesium

- Patrick Cozzi, Analytical Graphics Inc. and University of Pennsylvania

• Rest 3D

- Remi Arnaud, AMD


OpenCOLLADA Update

Uli Klumpp Sr. Director Engineering, Productivity & Graphics

Smith Micro Software July 24 2013


OpenCOLLADA Overview • High-quality, full functionality COLLADA importer/exporter library, plugins and

converter

- Released as open source on https://github.com/KhronosGroup/OpenCOLLADA

- Available free-of-charge for developers and tools vendors to integrate

COLLADAFramework

COLLADAMax COLLADAMaya COLLADA2glTF* Your project

here

*Repo: https://github.com/KhronosGroup/glTF

https://github.com/KhronosGroup/OpenCOLLADA

https://github.com/KhronosGroup/glTF


OpenCOLLADA Update • NetAllied has completed engineering

project to address known issues

• 3ds Max and Maya plugins now

- Available for 2013 versions*

- Conformance tested with CTS

• Fishing Cactus

- Contributing company, now code reviewer

• Great community involvement lately, but we want more!

• *Binaries:

https://github.com/KhronosGroup/OpenCOLLADA/wiki/OpenCOLLADA-Tools





AutomationML & COLLADA

Steffen Lips / NetAllied. [email protected]

mailto:[email protected]


What is ? • In factory automation, engineering is cost driver #1

• Many gaps and breaks in tool chains lead to using the “paper interface”

• AutomationML becomes the “Glue for Seamless Automation Engineering”

through

- Interoperability between software tools

- in all engineering phases,

- seamless and scalable,

- as open and standardized data format.


• AutomationML uses COLLADA for modeling geometric and kinematic data.

AutomationML Engineering data

CAEX IEC 62424 Top level format

Plant topology information

• Plants

• Cells

• Components

• Attributes

• Interfaces

• Relations

• References

COLLADA

Geometry Kinematics

PLCopen XML

Behaviour Sequencing

Object A

Object A 1

Object A 2

Init Init

Step 1

End

Further XML Standard format

Further aspects of engineering information

Object A n

…


A Station in Different Tools

Delmia V5

JT2Go

3DPDF

Sketchup


Update • Common

- New work group: Modeling of communication networks

• User support

- Conferences for users & implementers every year

- Publishing of implementation guidelines

• Marketing

- Congress „Digital Factory“, Berlin

- Fair “SPS/IPC Drives”, Nuremberg

- Article sequence in „SPS-Magazin“ (professional journal for automation)

• Standardization process

- AutomationML part 1 (topology) -> IEC FDIS (Final Draft International Standard)

- AutomationML part 2 (roles) -> IEC CDV (Committee Draft for Voting)

- AutomationML part 3 (geometry & kinematic) -> will be submitted in 2013/2014

© Copyright Khronos Group 2013 - © Copyright Khronos Group 2013 | Page

graphics library Transmission Format

Fabrice Robinet COLLADA Working Group Chair


Overview • Status

• Motivations

• Design principles

• glTF pipeline

• Scope

• glTF... side effects ?

• Demos


Status • COLLADA Working group initiative

• Work in progress - Not a ratified specification yet

• Code work and SPEC work at the same time

• SPEC currently catching up with the converter that implements the latest

decisions based on editor and community feedback

• Community feedback welcomed on GitHub


Motivations • Bridge the gap between 3D formats and GL based APIs.

• Reduce duplicated effort in content pipeline.

• A common format for contents providers.


Design principles • Streamline rendering: size, speed and ease of implementation

• Offload processing from runtime.

• Maps well to GL APIs and Typed Arrays.

• Neutral, specify higher level only when necessary.


OpenCOLLADA Compression

COLLADA2GLTF C++ Library

Rapidjson

COLLADA2GLTF command line tool

Rest3D transactions & access to 3D assets

COLLADA2GLTF Delivery Author Interchange API

Maya

Blender

..

glTF

OpenGL ES

WebGL

OpenGL

Converter

glTF Pipeline - overview

COLLADA


glTF Pipeline - COLLADA2GLTF • Mandatory transformations

- Triangulate

- Unify indices

- Split meshes

- Generate shaders

- Axis up conversion

• Planned optimizations & transformations

- Minify shaders

- Flatten hierarchy & combine meshes

- Convert images

- Compress meshes

- Interleave vertices

- ... Suggestions welcomed !


Scope • 1.0

- Node hierarchy

- Cameras

- Lights

- Key-framed animations

- Skinning

- Morphing

- Medias (images & videos)

• Mesh compression as extensions

• Multi-pass considered


Open3DGC • Open3DGC Binary is an implementation of the MPEG-SC3DMC (Scalable

Compression 3D Mesh Compression)

• K. Mammou, T. Zaharia, F. Prêteux, “TFAN: A low complexity 3D mesh

compression algorithm” Computer Animation and Virtual Worlds, Vol. 20(2-3),

pp. 343–354, 2009

• 2 modes: binary and ascii.

- Open3DGC Binary exploits an adaptive arithmetic-based encoding to exploit

statistical properties of the encoded data

- Open3DGC ASCII exploits a 7-bit ASCII encoding adapted for GZip compression

- Open3DGC ASCII is a slightly modified version of SC3DMC to exploit GZip

compression


Compression • Tested 2 compression libraries:

- Open3DGC: https://github.com/amd/rest3d/tree/master/server/o3dgc

- webgl-loader: https://code.google.com/p/webgl-loader/

https://github.com/amd/rest3d/tree/master/server/o3dgc

https://code.google.com/p/webgl-loader/




Model

COLLADA glTF glTF+Open3DGC

ascii

glTF+Open3DGC

binary

XML

gzip

raw gzip raw gzip raw •raw bin

•gzip JSON

• bin:102k

• JSON:11k

• bin:81k

• JSON:2kb

• ascii:29k

• JSON:11k

• ascii:19k

• JSON:2k

• bin:18k

• JSON:11k

• bin:18k

• JSON:2k

336k 106k 113k 83k 40k 21k 29k 20k

• bin:9220k

• JSON:75k

• bin:3220k

• JSON:5k

• ascii:3080k

• JSON:151k

• ascii:1510k

• JSON:11k

• bin: 1622k

• JSON:151k

• bin: 1622k

• JSON:11k

19767k 3417k 9295k 3225k 3231k 1521k 1773k 1633k

• bin:25224k

• JSON:183k

• bin:5738k

• JSON:8k

• ascii:7793k

• JSON:587k

• ascii:1433k

• JSON:29k

• bin:3205k

• JSON:589k

• bin:3205k

• JSON:29k

56763k 7378k 25407k 5746k 8380k 1462k 3794k 3234k

• bin:329k

• JSON:255k

• bin:99k

• JSON:10k

• ascii:122k

• JSON:267k

• ascii:61k

• JSON:11k

• bin:71k

• JSON:267k

• bin:71k

• JSON:11k

794k 133k 584k 109k 389k 77k 338k 88k


Compression: results overview

Data from rest3d SIGGRAPH 2013 BOF presentation, Khaled Mammou/Remi Arnaud


Open3DGC compression • First integration within “collada2gltf” available on GitHub.

- naive integration to be improved (leading to better compression)

• Encoder/Decoder in C++

• Just to get it working quickly, converted code using Emscripten to JavaScript

• Decoding performance to be evaluated in JS


“webgl-loader” compression • First integration within “collada2gltf” available on GitHub.

- naive integration to be improved (leading to better compression).

• Encoder in C++/Decoder in JS

• Fast decoding

Model COLLADA glTF+webgl-loader glTF+Open3DGC ascii glTF+Open3DGC binary

XML

gzip

raw gzip raw gzip raw •raw bin

•gzip JSON

• utf8:42k

• JSON:12k

• utf8:34k

•JSON:2kb

• ascii:29k

• JSON:11k

• ascii:19k

• JSON:2k

• bin:18k

• JSON:11k

• bin:18k

• JSON:2k

336k 106k 54k 36k 40k 21k 29k 20k

•utf8:8747k

• JSON:753k

•utf8:1325k

• JSON:29k

• ascii:7793k

• JSON:587k

• ascii:1433k

• JSON:29k

• bin:3205k

• JSON:589k

• bin:3205k

• JSON:29k

56763k 7378k 9500k 1354k 8380k 1462k 3794k 3234k


Compression: next steps • Fix integration issues: currently both Open3DGC and webgl-loader do not handle

shared vertex buffer by multiple index buffers. Needed some vertex duplication

to work-around this

• Benchmark for decoding performance and memory footprint.

• Compress animations, bones indices and weight


glTF side effects... ? • Package not only “models” but whatever you need a declarative way

• For instance, the viewer uses glTF “techniques” to:

- draw the background gradient

- setup the specific image based picking shaders


Demos • Montage Model Viewer

• MegaCity & Video demo

• Skinning


Thank you - See you on GitHub ! • Specification

- https://github.com/KhronosGroup/glTF/blob/master/specification/README.md

• Converter

- https://github.com/KhronosGroup/glTF/converter

• montagejs viewer

- https://github.com/fabrobinet/glTF-webgl-viewer

https://github.com/KhronosGroup/glTF/blob/master/specification/README.md








A glTF Loader for Three.js

Tony Parisi ViZi

July 24, 2013


Motivation • Three.js is the most popular WebGL Development Library

- Easy WebGL development using high-level scene graph API

- High-performance and feature rich

- Powers most of the popular WebGL applications and demo sites

- Dozens of active contributors; 6000+ commits, 2500+ forks, 12,000 favorites

- https://github.com/mrdoob/three.js/

• The content pipeline for Three.js is haphazard

- Simple popular formats supported (.OBJ, .STL) but those have limited feature set

(no cameras, lights, scenes, animations…)

- COLLADA is closest, but the Three.js loader is old, incomplete and buggy

- Three.js has defined its own file format, but the feature set is ad-hoc and non-

standard

- … as a result, developers are continually building custom pipelines and cobbling

formats; programmers are hand-coding layouts, lighting and animations.

- This is not a recipe for scaling up WebGL deployment!

https://github.com/mrdoob/three.js/


A glTF Loader for Three.js • glTF is an ideal candidate for a complete, open, industry-standard modern

format for use with Three.js

- Implements most features required by modern 3D applications: scenes; cameras;

lights; animations (articulated, skinned, morphs); shaders; multi-pass techniques.

- JSON- plus binary-based approach is very web-friendly

- More compact representation promises much faster load speed and smaller

memory footprint than XML-based COLLADA

- COLLADA2GLTF converter provides ready-to-go path for existing tools that export

COLLADA

With this solution in place, Three.js developers can get back to writing code

instead of wrangling pipelines… and leave the art to the artists!


The Project • Currently a branch of the glTF project on Github

- https://github.com/KhronosGroup/glTF

- Branch ‘threejsloader’

• Designed to be compatible with other Three.js example loaders such as OBJ and

COLLADA

- e.g. http://threejs.org/examples/webgl_loader_collada.html

- No external dependencies other than official glTF parser (webgl-tf-loader.js)

• Demo version at SIGGRAPH

• Expect completion of initial

implementation in August

• After completion, will submit a Github pull

- request for inclusion with

Three.js distribution

https://github.com/KhronosGroup/glTF

http://threejs.org/examples/webgl_loader_collada.html


Status • Most glTF features are already supported

- Triangle Meshes

- Materials – diffuse, specular, emissive, ambient, textures, environment maps

- Cameras – perspective and orthographic

- Lights – ambient, spot, point, directional

- Matrix transforms

- Scene structure

- Animation - Key frame/articulated only

- Shaders - Uses “common profile” techniques - common lighting models such as Phong and

Lambert, and their parameters, are mapped to existing Three.js material types

• TBD features

- Arbitrary GLSL shaders (via Three.js ShaderMaterial)

- Skinned animations and morphs


glTF in Cesium

http://cesium.agi.com/

http://cesium.agi.com/

collada/gltf bof - khronos group · collada/gltf bof siggraph 2013 ... smith micro software july 24...

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