3D symbols for point data: spheres and beachballs

[Stuart Wier <wier@xxxxxxxxxx>]

Needing to make small 3D symbols for point data, spheres in particular, 
I am using code like that in the ucar.visad package, class 
ShapeUtility.java, which creates VisADGeometryArray-s by specifiy the
xyz locaiton of every vertex, and a normal for each vertex and face.
See the 3d pyramids in the figure at the bottom of
 http://geon.unavco.org/unavco/IDV_for_GEON.html
The VisADGeometryArray and the ShapeUtility code allows the
needed feature of resizing the shape and setting a color.  But making a 
sphere looks difficult, since it is not a simple
polygon with flat faces. Has someone a solution?

Looking ahead, I need to color the sphere in panels (gores) like a
beachball for earthquake focal mechanisms. See
http://quake.wr.usgs.gov/recenteqs/beachball.html
Any ideas?

Chiao

Stuart Wier

UNAVCO