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Author(ing)
Author, auctorem : "enlarger, founder" or literally “someone causing growth"
Programmer Designer
Content Driven
Tool Driven
Authoring & Content Design– Problem Framing
• Analyze the reported “problem”– Task Analysis
• Domain: common themes, interactions • Objectives: goal of the user• Limitations: identify limits
– Structuring/Segmentation• Real World• Virtual World
– Description and Meaning• Logical Connection between elements
Problem Framing: Wicked Problem
• Introduced by Horst Rittel and Melvin Webber:– No definition– Ill-defined problems– Pre-empted solutions– Circular problem dependencies (no stopping
condition)
“The Problem”“The Problem”
Problem Framing
Identify all angles of a problem
Restate the Problem
Reformulate
Identify Sub-problems
Problem Solving
• Discovering Design, Richard Buchanan, Victor Margolin, University of Chicago Press
SetupSetup
InteractionInteraction
ErgonomicsErgonomics
ContextualCoherenceContextualCoherence
Physical and Virtual
Content Design
Physical and Virtual
Content Design
Physical
Virtual
Small recap
• Traditional 3D content creation can not foster the possibilities of AR
• Developing AR application needs extra attention on solving the right problem
• Merging virtual and real environments needs attention on the domain, context and the goals of the user
Augmented Reality IssuesRegistration
Relation between real and virtual world
Occlusionawareness of parts of the scene that are not augmented
Impact of Augmentationchange meaning, obstruct or alter
Reality-Virtuality Relationship
• Contextrelation of virtual content and real world
• Perceptionvisual or aural appearance
• Ontologymeaning of augmentation
• Collaboration / Participation social impact and engagement
Aspect: Context
• Functional and visual context relationship
• Embedding of virtual content as extension or alteration
Picture Courtesy: Patrick Baudisch
Aspect: Context• Registration
– Degree of Freedom (DOF) used
• Interaction– Proximity– Visibility– Orientation– Occlusion
Functional Context in AR
Augmented Kitchen: Spatial Reality AR Soccer: Mobile AR
Context Spatial, Aiding Augmentation Context: mobile fiducial and
visualisation
Aspect: Ontology
• Ontology: Meaning and nature of things– Affordance
• Relation of objects and subjects• James J. Gibbson (other variants by Husserl, Norman)
– Augmentation• Hide or enhance meaning• New meaning through overlay
Relevance of Affordance
WIMPWindow, Icons, Menu, Pointer
Collaboration an afterthought
Virtually no difference between text processor and 3D modeling tool
Affordance
• Property describing the relation of objects
• Gibson: Affordances (1979, General)
• Norman (1988): – Actual Affordances– Perceived Affordances
lets me throughcan be opened
perceived actual
Aspect: Collaboration
• Engagement– Involving– Modes (direct access)
• Interactivity• Sharing
– Policies– Locking
Tangible AR Design Principles
• Tangible AR Interfaces use TUI principles– Physical controllers for moving virtual content– Support for spatial 3D interaction techniques– Time and space multiplexed interaction– Support for multi-handed interaction– Match object affordances to task requirements– Support parallel activity with multiple objects– Allow collaboration between multiple users
Mixed Reality Continuum
Hypothesis– The next generation of interfaces will support transitions
along the Reality-Virtuality continuum
Reality(Tangible Interfaces)
Virtuality(Virtual Reality)
Augmented Reality (AR)
Augmented Virtuality (AV)
Mixed Reality (MR)
Milgram (1994)
The MagicBook
Design Goals– Allows user to move smoothly between reality
and virtual reality– Support collaboration
Features
Seamless transition between Reality and Virtuality– Reliance on real decreases as virtual increases
Supports egocentric and exocentric views– User can pick appropriate view
Computer becomes invisible– Consistent interface metaphors– Virtual content seems real
Supports collaboration
Technology
• Reality– No technology
• Augmented Reality– Camera – tracking– Switch – fly in
• Virtual Reality– Compass – tracking– Press pad – move– Switch – fly out
Summary
• Context awareness is paramount• AR can alter, obscure or hinder depending on
the integration, visually or functional• AR can change meaning of objects: be aware
of perceived affordances• AR is not necessarily standalone: transitional
methods can help to blur boundaries
Traditional 3D Content Design and AR
• No context awareness• No feedback within the
real environment• Limited interactivity of
content
Challenges for AR authoring
• Store contextual information• Define relationships between real and virtual
environments• Override management: virtual or real first
priority in interaction (e.g. physics)• Feedback loop: prototype interaction
metaphors
Authoring Approaches
• Build within– Develop concepts and
content on the fly– Merged runtime and
design time
• Design and Run– Develop concepts and
content externally– Divide runtime and
design time
Tools for AR Development
• ToolkitsComputer VisionRendering
• FrameworksInfrastructureModel Loader
• Authoring ToolsGUIInteraction Design
High Level
Low Level
Low Level Toolkits
AR Toolkithttp://artoolkit.sourceforge.net/
MXR Toolkithttp://mxrtoolkit.sourceforge.net/
MR Toolkit
Frameworks
Studierstubehttp://studierstube.icg.tu-graz.ac.at
DWARFhttp://ar.in.tum.de/Chair/ProjectDwarf
VHD++http://vhdpp.sourceforge.net/
AR Authoring
AMIREhttp://www.amire.net/index.html
DARThttp://www.gvu.gatech.edu/dart/
APRILhttp://studierstube.icg.tu-graz.ac.at/april/
Audiences for Authoring Tools
• Content creation and assembly for a wide audience
• Unspecific about the supported interactions
• Specific for a target audience
• Support domain related context
Designer AR Toolkit: DART
Using Director as a base for AR authoring and utilizing the infrastructure of the tool it embeds in
Authoring and Storage
• Traditional– VRML (original MagicBook)– OpenFlight– 3D studio– Maya / Studio Tools
• AR related– APRIL
VRML (Virtual Reality Markup Language)• Originates sgi Open Inventor format
– Replication of Scenegraph structure• Version 1.0• Version 2.0 (VRML97) ISO standard
– Support for videotextures, sensors etc.– New syntax
• X3D– XMLyfied VRML97– Programmable shaders– Extensible through XML namespaces
• Check http://web3d.org
Disadvantages
• No support yet for context awareness– Web3D consortium is discussing an extension to
X3D to change this (First proposal submitted in 2007)
• Only very limited support in non-commercial libraries
• Hint on the side: Don’t use the VRML support in AR Toolkit
Summary
• AR content can be developed: from within and externally
• Like in traditional 3D content development there is a differentiation between domain specific and generic tools
• Existing 3D storage solutions do not honour specifics of AR
ComposAR
• Persistant storage for Scenes• Cross platform consistent GUI• Import from various 3D content creation tools
(Maya, 3ds max etc)• Highly configurable
osgSWIG
• Thin Meta API for OpenSceneGraph and osgART
• Wrapper for– Java, C#, Python, Ruby, Lua
• WrapperWrapper for osgIntrospection– Transparent cross-language Script within Script