[Gzz-commits] manuscripts ./gzigzag.bib xupdf/article.rst

[Janne V. Kujala]

CVSROOT:        /cvsroot/gzz
Module name:    manuscripts
Changes by:     Janne V. Kujala <address@hidden>        03/02/10 12:49:33

Modified files:
        .              : gzigzag.bib 
        xupdf          : article.rst 

Log message:
        reorg buoy section, add ref in bib

CVSWeb URLs:
http://savannah.gnu.org/cgi-bin/viewcvs/gzz/manuscripts/gzigzag.bib.diff?tr1=1.19&tr2=1.20&r1=text&r2=text
http://savannah.gnu.org/cgi-bin/viewcvs/gzz/manuscripts/xupdf/article.rst.diff?tr1=1.48&tr2=1.49&r1=text&r2=text

Patches:
Index: manuscripts/gzigzag.bib
diff -u manuscripts/gzigzag.bib:1.19 manuscripts/gzigzag.bib:1.20
--- manuscripts/gzigzag.bib:1.19        Sun Feb  9 22:59:11 2003
+++ manuscripts/gzigzag.bib     Mon Feb 10 12:49:32 2003
@@ -2404,6 +2404,15 @@
     year = "1996",
     url = "citeseer.nj.nec.com/plaisant96lifelines.html" }
 
address@hidden wang01mindsviews,
+    author = "Wang, H. and Johnson, T.R. and Zhang, J.",
+    year = "2001",
+    title = "The mind's views of space",
+    booktitle = "Proceedings of the 3rd International Conference of Cognitive 
Science",
+    location = "Beijing, China",
+    pages = "191-198",
+    url = 
"http://acad88.sahs.uth.tmc.edu/research/publications/iccs2001spatial.pdf";
+}
 
 @comment -------------------------------------
 @comment Windowing
Index: manuscripts/xupdf/article.rst
diff -u manuscripts/xupdf/article.rst:1.48 manuscripts/xupdf/article.rst:1.49
--- manuscripts/xupdf/article.rst:1.48  Mon Feb 10 08:34:08 2003
+++ manuscripts/xupdf/article.rst       Mon Feb 10 12:49:33 2003
@@ -265,39 +265,82 @@
 
 - can smoothly adjust buoy size and location 
 
+We draw the link targets as buoys around the focus.
+
+Layout requirements:
+
+    - buoys should not be placed over the focus 
+
+    - buoys should be placed close to their anchors
+
+    - buoys anchored closer to the focus should be larger
+
+    - the layout should animate continuously when the focus moves
+
+Furthermore,
 It is important to maintain orientation locally (i.e., left/right
 direction of links, etc.) but the space need not be globally
 euclidian. This matches the way the brain understands space
 as globally distorted, segmented, locally Euclidian views.
 Some refs (should search for more/better):
 http://acad88.sahs.uth.tmc.edu/research/publications/iccs2001spatial.pdf
+[#wang01mindsviews]_
 http://citeseer.nj.nec.com/hunt99orientation.html
 
-Because of this, each link has a specific left-right orientation ...
+That is, going in one direction should result in arriving from 
+the opposite direction.
 
-Geometry:
+Because of this, each link has a specific left-right orientation 
+so that a right-end buoy is drawn on the right side of the view
+and a left-end buoy on the left side.
 
-  - buoys on a circle
+More than two opposing directions could also be used, but
 
-       - matches fisheye shape
-       - other reasons?
-       - why not simply straight lines on left/right sides?
+       - it is not required for maintaining the sense of direction
 
-  - projected from a constant point (on left/right) through the 
-    anchor to right/left side of the circle
+       - it would limit the layout of a large number of buoys
 
-       - projections are easy to track for humans
+       - there is usually no meaningful global 2D layout of a network 
+         of nodes; in our application, the structure has simply
+         directed links, visualized as the left-right direction.
 
-  - final positions may be adjusted to prevent too much overlap
+The horizontal orientation is more natural than, e.g., vertial, because
+the visual field is wider than it is tall
+(exemplified by the usual screen aspect ratios of 4:3 and 16:9) 
+leaving more space at the left and right sides than on the top and bottom.
+XXX: left and right hand???
 
-       - how does this interact with the perception of the projection?
+We choose the geometry as follows:
+
+  - buoys are placed on a circle centered at the focus and diameter 
+    little less than the screen height
 
-  - buoys far from the focus are drawn at the anchor instead
+       - buoys equally close to the focus, matching the fisheye focus shape
+
+       - provides more space for the buoys than, e.g., a straight line
+         (a circle arc is longer)
+
+  - buoys anchored outside the buoy-circle are drawn near the anchor instead,
+    to prevent awkward view-cutting long lines and to yield more space
+    for the layout of buoys anchored closer to the focus
+
+  - the position on the circle is obtained by projecting from a constant 
+    point (on left/right) through the anchor to right/left side of the circle
+
+       - buoys placed close to the anchor
+
+       - such line projections are easy to track for humans,
+         because it is analogous to 3d perspective
+
+  - final positions may need be adjusted to prevent too much overlap
+
+       - how does this interact with the perception of the projection?
 
-  - buoy scale
+  - buoy scale is relative to the anchor's distance from the circle
+       
+The above design produces good results and is very simple if not 
+the simplest way to meet the layout requirements.
 
-       - buoys closer to the focus should be larger
-       - scale is relative to the anchor's distance from the circle
 
 Break lines
 -----------