volume rendering for VisAD

VisAD now includes volume rendering - that is rendering a
3-D Field as a transparent fog.  This is only applied for
Fields (generally FlatFields) whose domain Set is a
Linear3DSet, when the 3 domain RealTypes are mapped to
XAxis, YAxis and ZAxis, when range values are mapped only
to color, Alpha and RangeSelect, and when texture mapping
is enabled and point mode is disabled in the
GraphicsModeControl (these are the defaults).

Note that unless some value if mapped to Alpha in such a way
that most "outer" volume samples are pretty transparent, the
volume image will be a boring solid block.

visad/examples/Test61.java illustrates how to use volume

If you want volume rendering for a FlatField whose domain Set
is not a Linear3DSet, you can use the FlatField's resample
method to resample the FlatField's values to a Linear3DSet.

Experience with Vis5D and other systems has shown that volume
rendering can make interesting images for publication but is
less useful for day-to-day data analysis.

Bill Hibbard, SSEC, 1225 W. Dayton St., Madison, WI  53706
hibbard@xxxxxxxxxxxxxxxxx  608-263-4427  fax: 608-263-6738