Pad : A Zooming Graphical Interface for Exploring Alternate Interface Physics

1
Pad A Zooming Graphical Interface for
Exploring Alternate Interface Physics

• Presented By
• Daniel Loewus-Deitch

2
Introduction

• Pad is a zooming graphical interface.
• Possible alternative to traditional windows/icon
  interface design.
• A different direction than many other groups
  exploring 3D virtual worlds.

3
Metaphor vs. Physics

• Metaphor-based approaches have certain
  limitations
• Too much focus on old media.
• Underutilizing potential of mechanisms associated
  with new computerized media.
• Physics approach views interface design
  differently
• Appearance and behavior of informational objects.

4
Metaphor vs. Physics

• Examples of informational physics
• Useful representations to show extent of use for
  an object (i.e. dog-eared pages in real world).
• History-enriched digital objects.
• New physics for interacting with graphical data
  (i.e. zooming).

5
Metaphor vs. Physics

• 4 problems with metaphor-based model
• Metaphors always pre-exist their use.
• Metaphor must be familiar.
• Limits resources and choices.

6
Metaphor vs. Physics

• Metaphors are temporary bridging concepts.
• Eventually they die as a metaphor and take on a
  common meaning in the computer environment.
• After metaphor dies, it can still restrict
  functionality when trying to keep the metaphor
  from being violated.
• Metaphor-based interface is not easily scalable.
• Metaphors may lead users to expect functionality
  associated with the source object that is not
  actually included in the interface.

7
Metaphor vs. Physics

• Issues with physics-based model
• Cant rely on user familiarity to same extent
  (learnability consequences).
• Make sure physics mechanisms are easily
  discoverable and learnable.

8
Motivation

• Desktop metaphor has hit a dead end.
• Present large amounts of information with the
  same rich structure and dynamic character of the
  real world.
• Create physics that symbolically relate to
  informational objects and exploit semantic
  relationships.
• Attempting to fully utilize our natural spatial
  abilities.

9
Motivation

• Pad provides more choices than just the
  inclusion or exclusion of information.
• Make it easier to find specific information in
  large dataspaces.
• Complements traditional filtering and
  recommendation approaches.
• Highly rated information is largest.
• Lower rated information is smaller and off to the
  side.

10
Pad System

• General purpose
• Supports these standard objects
• Colored text
• Text files
• Hypertext
• Graphics
• Images
• Zooms around current cursor position.

11
Pad System

• Originally designed for use with a 3-button
  mouse.
• Semantic zooming
• When zoomed out, object is represented
  differently. It is not just scaled down.

12
Recent Advances

• Focus on smooth zooming with large graphical
  datasets.
• Essential that frame rates be consistently
  maintained because of nature of interaction.
• Coded in C

13
Efficiency

• New efficiency methods
• Spatial indexing
• Restructuring
• Spatial level-of-detail
• Clipping
• Refinement
• Adaptive render scheduling
• Search for balance between local detail and
  global context.

14
Efficiency

• Parallel lazy loading
• Helps avoid start-up costs of parsing and loading
  database when accessing external information
  sources.
• Only loads portion of database that is currently
  visible.
• Performed in background.
• Ephemeral objects
• Automatically deleted if not viewed within
  several minutes.

15
Hypertext

• Multiscale layouts
• Graphically represent parent-child relationship
  between links.
• Linked data is loaded to side and made smaller.
  Then view is animated to center new data.

16
Interface to TCL/TK

• 3 classes
• Create objects
• Handle objects
• Render scene
• Every object assigned a unique integer id.
• Procedural objects support semantic zooming.

17
Interface to TCL/TK

• Navigation and search mechanisms provided.
• Most of panning is performed while zoomed out.
• Gives sense of context.
• Speeds up animation.

18
Visualizations

• Pad directory browser
• For viewing large hierarchical databases.
• Square frame directory
• Solid square file
• Text names shown when zoomed in.
• Search by zooming in and out of directory tree or
  by content-based search.
• Zooming into file loads text inside colored
  square.

19
Visualizations

• Timeline
• Helpful to look at history using different
  scales.
• Zoom into particular years to see content in
  detail.