Information Visualization Using 3D Interactive

Animation

Meng Tang

05/17/2001

George G. Robertson, Stuart K. Card,

and Jock D. Mackinlay

MotivationsMotivations

GoalLower the cost of finding information and accessing it

StrategiesMaking the user’s immediate workspace largerEnabling user interaction with multiple agentsIncreasing the real-time interactionUsing visual abstraction to speed information

assimilation and retrieval.

Technology AdvancesTechnology Advances

3D graphics hardware 3D transformations, hidden-surface removal, double-

buffered animation, antialiasing, lighting and surface models.

3D graphics librariesOpenGL, PEX

Information VisualizerInformation Visualizer

Information Access vs. Document Retrieval

Information Access vs. Document Retrieval

Document retrievalInterest --> documentsRecall & Precision

Document retrieval is part of information useInformation is used to produce more informationNew information is usually at a higher level of

organization relative to some purpose

Information WorkspacesInformation Workspaces

A virtual environment for finding information and accessing it.

Not just with the retrieval of information from a distant source, but also with the accessing of that information once it is retrieved and in use

Rooms SystemExtend the desktop to multiple workspaces.User can switch among multiple workspaces.

Information WorkspacesInformation Workspaces

Information WorkspacesInformation WorkspacesImproving rooms system

Objective: Decrease the costs for performing information-intensive tasks, or,

alternatively, to increase the scope of information that can be utilized for the same cost.

Method:Large Workspaces -- Make the immediate workspace virtually largerAgents – Delegate part of the workload to semiautonomous agentsReal-Time Interaction – Maximize the interaction ratesVisual abstractions – Speed assimilation and pattern detection

Information WorkspacesInformation WorkspacesSystem Goal TechniquesLarge workspace to reduce access cost

More screen space -> RoomsDenser screen space -> Animation, 3D

Offload work to agents Search -> search agentsOrganizing -> clustering agentsInteracting -> Interactive Objects

Maximize real-time interaction rates

Rapid interaction, Tune to human constants -> Cognitive Coprocessor schedule and Governor

Visual abstraction to speed pattern detection

Information Visualizations:Hierarchical structure -> Cone TreeLinear structure -> Perspective WallContinuous data -> Data SculptureSpatial data -> Office Floor Plan

UI ArchitectureUI ArchitectureSeveral Problems

Multiple Agent Problem: How can system manage the interaction of multiple asynchronous agents.

Animation Problem: How can system provide smooth interactive animation

Interaction Problem: How can 3D widgets be designed and coupled to appropriate application behavior.

Viewpoint Movement Problem: How can the user changed the point of view rapidly and simply

Object Movement Problem: How can objects be easily moved about in a 3D space

Small Screen Space Problem: How can the dynamic properties of the system be utilized to provide the user with an adequately large work space.

UI ArchitectureUI ArchitectureProblem Problem Solution

Multiple Agent Problem Cognitive coprocessor scheduler

Animation Problem Cognitive coprocessor scheduler and Governor

Interaction Problem Interactive objects

Viewpoint Movement Problem Point of interest logarithmic flier

Object Movement Problem Object of Interest logarithmic manipulator

Small Screen Problem 3D/Rooms and 3D visualization

Cognitive CoprocessorCognitive Coprocessor

What is Cognitive CoprocessorAn animation loop and a scheduler for agentsAn impedance matcher between the cognitive and perceptual

information processing requirements of the user and the properties of these agents

3 sorts of time constantsPerceptual processing time constant (0.1sec)Immediate response time constant (1sec)Unit task time constant (5~30sec)

Cognitive CoprocessorCognitive Coprocessor

Perceptual processing time constantGovernor: reduce the quality to keep the frame rate.

Immediate response time constantAgents provide status feedback at intervals no longer than this

time constantImmediate response animation

Unit task time constantTime to complete a taskUser can start the next request as soon as sufficient information

has developed from the last request or even in parallel with it

Cognitive CoprocessorCognitive Coprocessor

Interactive ObjectsInteractive Objects

Interactive objectsBasic building block in the Information VisualizerGeneralization of Rooms Buttons2D/3D appearanceAllow mouse-based input (press, rubout, check, flick)

3D Navigation and Manipulation

3D Navigation and Manipulation

Overview Doors Walking metaphorPoint of interest logarithmic flightObject of interest logarithmic manipulation

Information VisualizationInformation VisualizationGoal:

Attempts to display structural relationships and context that would be more difficult to detect by individual retrieval requests.

5 sorts of data organizationsHierarchical: Cone TreeLinear: Perspective WallSpatial: Structural browserContinuous Data: Data sculptureUnstructured: Information grid

Cone TreeCone Tree

Cone TreeCone Tree

Properties of Cone TreeEach layer has cones of the same heightCone base diameters for each level are reduced in a

progression so that the bottom layer fits in the width of the room.

Body of each cone is shaded transparentlyText is shown only for the selected path

Manipulation of Cone TreeSelect nodes

Cone TreeCone Tree

Advantagesthe use of interactive animation to move some of the cognitive

load to the human perceptual systemUsing the depth to fill the screen with more informationAspect ratio of cone tree is fixedFisheye view (brighter, closer, larger)

DisadvantagesComplex user interactions to access some of the informationfixing the aspect ratio limits the number of levels of the cone

tree

Cone TreeCone Tree

Perspective WallPerspective Wall

Obstacles to a visualization of linear information structuresThe large amount of information that must be displayedThe difficulty of accommodating the extreme aspect ratio of the

linear structure on the screen.Disadvantages of Overview-Working View structure

Important contextual information, such as the neighborhood of the viewing region is just as small as unimportant details

Increase the space of overview leads to reduce the space of working view

Perspective WallPerspective Wall

AdvantagesIntegrate detailed and contextual views Smooth transitions of viewsRetain any 2D task-specific featuresNo special large- and small-scale versions of items

must be designedRatio of detail an context is adjustable

Tracing Data Paths in 3D Graphics

Tracing Data Paths in 3D Graphics

Tracing Data Paths in 3D Graphics

Number of errors in detecting paths in tree structures is substantially reduced if a 3D display method is used.

A tree structure is not necessarily a good candidate for 3D visualization