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revision 1.31 by tjl, Tue Feb 4 06:42:29 2003 UTC revision 1.32 by jvk, Tue Feb 4 12:56:06 2003 UTC
# Line 144  There have been various attempts to alle Line 144  There have been various attempts to alle
144    they show thumbnails, or what they show).    they show thumbnails, or what they show).
145    Emphasis seems to be on the methods for generating the f+c structure,    Emphasis seems to be on the methods for generating the f+c structure,
146    i.e., finding landmarks, paths between nodes, what nodes to show, etc.    i.e., finding landmarks, paths between nodes, what nodes to show, etc.
147    Some features use in the example views:    Some features used in the example views:
148    
149          - nodes are shown as cubes (focus node as a sphere) with titles          - nodes are shown as cubes (focus node as a sphere) with titles
150          - node size/height/color depicts importance/access frequency          - node size/height/color depicts importance/access frequency
# Line 302  of different places. Line 302  of different places.
302    
303  When a link is followed, the torn shape of the target buoy  When a link is followed, the torn shape of the target buoy
304  animates to the full shape of the document, as if larger and  animates to the full shape of the document, as if larger and
305  larger parts were torn off.  larger parts were torn off. [XXX: screenshots]
306    
307  The hardware implementation uses a noise texture for creating  The hardware implementation uses a noise texture for creating
308  the variation in the torn shape with texture coordinates tied  the variation in the torn shape with texture coordinates tied
# Line 345  as demonstrated in Fig.XXX Line 345  as demonstrated in Fig.XXX
345  Paper  Paper
346  -----  -----
347    
348  - fragments of documents are shown  Although the silhuettes of the buoys are different,
349    the fragments of the documents still seem quite similar.
350    The user could identify the related documents by
351    reading the text of a fragment, but that requires attention.
352    
353      - fragments of PDF files seem similar; target fragment  Using a unique background texture for each document changes the
354        not useful per se  situation dramatically: the user can perceive the identity
   
     - using a unique background texture for each, situation  
       dramatically changes.  
   
 A unique background texture consisting of random shapes  
 and colors is chosen for each document using the identity as a seed.  
 The background textures help the user perceive the identity  
355  of the most familiar documents at a glance,  of the most familiar documents at a glance,
356  even when only fragments are shown.  even when only fragments are shown.
357    Furthermore, when moving from node to node, the pre-attentive
358    cues of identity help the user maintain a sense of direction.
359    
360    The background textures are randomly chosen using the identity as a seed.
361    That is, each document has a unique backround texture, but the texture
362    is not in any way related to the contents of the document (except
363    that a hash of the contents could be used as an identity of an immutable
364    document).
365    That way, the textures in any view are as different as possible,
366    even if the documents are similar.
367    Furthermore, the unique background of any document can be instantly drawn,
368    as soon as the identity inside the system is known.
369    
370  The distribution of the textures is designed to be maximally  The distribution of the textures is designed to be maximally
371  diverse and recognizable using a rough, qualitative model  diverse and recognizable with respect to a rough, qualitative model
372  of visual perception.  of visual perception.
373  For example, backgrounds with random pixels would all  For example, backgrounds with random pixels (noise) would all
374  look the same, because the pixels are not perceived individually.  look the same, because the pixels are not perceived individually.
375  However, shapes and overall colors can be independently random to  However, shapes and overall colors should be independently random to
376  maximize diversity.  maximize diversity.
377  Making the backgrounds repeating creates well-defined patterns  Making the backgrounds repeating creates well-defined patterns
378  and improves recognizability when fragments are shown.  and improves recognizability when fragments are shown.
379    
380  - readability  Our hardware implementation (libpaper) uses a small set
381  - preattentive  of *basis textures*, which are non-linearly combined on the
382    GPU to create a large set of recognizable shapes.
383    The coordinates of the component textures are
384    randomly chosen affine functions of the paper location,
385    but repeating with a randomly chosen *repeating unit*
386    (a parallelogram).
387    
388    At each pixel, the combined values of the basis textures
389    are used for interpolating between the colors
390    of a small, randomly chosen palette of *compatible* colors.
391    That way, the colors and shapes are independently random
392    and the palette can be restricted to light colors to
393    maintain readability.
394    
 - hw accelerated impl (libpaper)  
         - colors  
         - basis textures  
         - texcoords, repeating units  
         - combiners  
395    
396  Implementation on the Gzz platform  Implementation on the Gzz platform
397  ==================================  ==================================

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