Hi Raymond,
Determining visibility of points in a terrain plot is a bit
tricky, and I don't think picking logic will help much.
You could use the Java3D Transform to transform the data
coordinates of your points into 3-D (x, y, z) screen
coordiantes, then for each point see if there is a point
at the same approximate x with smaller z (i.e., closer)
and larger y (i.e., higher and thus obscuring). The x test
has to be approximate since your points won't fall on neat
rows and columns once transformed into 3-D screen coords.
Note that a point might also be technically visible (from
underneath the terrain surface) if all the points in front
of it in z have larger y.
Good luck,
Bill
----------------------------------------------------------
Bill Hibbard, SSEC, 1225 W. Dayton St., Madison, WI 53706
hibbard@xxxxxxxxxxxxxxxxx 608-263-4427 fax: 608-263-6738
http://www.ssec.wisc.edu/~billh/vis.html
