reduced VisAD memory use; SelectValue bug fixed

VisAD should now use less memory for transforming data into
displays - much less in some cases.
 
One of the changes is the use of bytes rather than floats to
represent red, green, blue and alpha color components.  This
is tricky, since Java3D wants colors as unsigned bytes, which
are not a primitive data type of Java.  If you are creating
VisADGeometryArray "shapes" and accessing the "colors" field,
please note that it has changed from "float[]" to "byte[]"
(see visad/examples/Test46.java).
 
Note that computing iso-surfaces from regular and irregular
grids still consumes pretty much memory for large grids - that
is the nature of the computation and similar to our experience
with Vis5D.
 
Other improvments in VisAD's display logic are in the works.
For example, faster display of images in curved coordinate
systems, and volume rendering.
 
The current changes also include the fix for the SelectValue
bug that Doug Lindholm found.
 
Cheers,
Bill
 
----------------------------------------------------------
Bill Hibbard, SSEC, 1225 W. Dayton St., Madison, WI  53706
whibbard@xxxxxxxxxxxxx  608-263-4427  fax: 608-263-6738
http://www.ssec.wisc.edu/~billh/vis.html