pad++ a zooming graphical sketchpad for exploring alternative interface physics benjamin b....
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Pad++A Zooming Graphical Sketchpad for Exploring Alternative Interface Physics
Benjamin B. Bederson, James D. Hollan, Ken Perlin, Jonathan Meyer, David Bacon, George
Furnas
Presented by Evren Sirin
Overview Motivation Description of Pad++ Visualization Examples with Pad++ Space-Scale Diagrams Procedural Animation Implementation Critique
Motivation Massive amount of information Current metaphor-based approach is
limited When designing with metaphors you are
limited to those that exist Metaphors don’t scale easily to larger amounts
of data Metaphors only bridge concepts temporarily Metaphors may be misleading
The alternative is to design using interface physics
Informational Physics Strategy View information at multiple scales
Elastic stretchable infinite sheet Semantic zooming
Make it more intuitive and easier to find specific information in large data spaces Filter or recommend a subset of the data Provide a useful substrate to structure
information
What is Pad++ A general-purpose substrate
creating and interacting with structured information based on a zoomable interface
PadDraw: Real application based on Pad++
Description Intuitive navigation
Animated panning & zooming Visual searching + Content-based search
Portals Provide views onto other areas (+filtering) Index: sticky portal
Lenses Portals that change the way objects presented
Semantic zooming Change the way things look depending on their
size
Visualization Examples Variable resolution for
representation & interaction There is always more room to put
information “between the cracks” Suitable for visualizing hierarchical
data
HTML Browser
Directory Browser
TimeLine
Oval Document Layout
Space-Scale Diagrams Analytical tool for describing
multiscale spaces Static representation of
multiscale movements Used to solve two basic problem
Joint pan & zoom Shortest paths between two points
Simple space-scale diagram
A one dimensional space-scale diagram of six points as the view zooms in from (a) to (b) to (c) around the point q
Pan-zoom trajectories
Basic pan-zoom trajectories are shown in the heavy dashed lines. (a) is a pure pan, (b) is a pure zoom (out), and (c) is a zoom around the point q
Solving joint pan-zoom problem
Solution to the simple joint pan-zoom problem. The trajectory s monotonically approaches point (x2, z2) in both pan and zoom
Shortest path between two points
Each arrow represents one unit of cast. Because zoom is logarithmic, it is often "shorter" to zoom out (a), make a small pan (b), and zoom back in (c), than to make a large pan directly (d)
Procedural Animation User-definable animated objects To support an informational physics in
which objects animate naturally Clearly structured animated narrative vs.
assortment of disjoint temporal events Simple widgets defined at a behavioral
level Zoomable Choice Widget
Implementation Substrate implemented in C++ Scripting language interface
Easily extensible (no need for C++ code) Implemented as a widget in Tcl/Tk
Efficient byte-compiled language: KPL Efficiency results
600,000 Objects & 10 frames/sec Rendering times # of visible objects
Efficiency methods Spatial Indexing Clustering Refinement Level-Of-Detail Region Management Clipping Adjustable Frame Rate Interruption Ephemeral Objects Optimized Image Rendering
My favorite sentence
If interface designers are to move beyond window, icons, menus, and pointers to explore a larger space of interface possibility, additional ways of thinking about interface that go beyond the desktop metaphor are required.
Contributions Alternative to WIMP
Informational physics strategy for interface design
Exploring potentially more effective computer-based mechanisms
Space-Scale Diagram Analytical tool for multiscale spaces
Notes on the references Sketchpad, Sutherland
The first interactive computer graphics Pad, Perlin & Fox
Semantic Zooming, Portals Constraint-Based Drawing, Borning Generalized Fisheye Views, Furnas Perspective wall, Card, Robertson & Mackinlay
visualizing linear information by smoothly integrating detailed and contextual views.
Information Visualizer, Card Information workspace, Cone-trees
Strengths Effective complement to traditional
metaphor-based approaches Space-Scale Diagram
Weaknesses No experiment on HCI metrics Orientation problems: Zooming loses
overview Jump back & forth between topics
Critique
What has happened to this topic? Pad++: version 0.9 available in UCSD Jazz: in UMD
General-purpose 2D graphics toolkit for creating ZUI CounterPoint: Zoomable presentation tool KidPad: a collaborative story authoring tool for
children PhotoMesa: Zoomable image browser
Zomit: generic package for developing ZUI Visualize biological data and to navigate in a large
space of biological information
Outline view
Zoom into files
Read contents
Zoom out & pan
Create a portal
Move away the copy
Portal is NOT a copy
Pan & zoom in a portal