user-defined color tables; cross sections

Bill and all:

First, please remind me how to create a set of pre-defined
color tables, and apply them to a display. I found this
much in the mail list archive:

"you could try computing a color table:

  ColorControl control = (ColorControl) cmap.getControl();
  float[][] table = new float[3][256];
  for (int j=0; j<256; j++) {
    table[0][j] = ... // j-th red
    table[1][j] = ... // j-th green
    table[2][j] = ... // j-th blue

then how do I use a ColorControl?

And is there a VisAD example that shows how to
create a cross section (2D display) for a plane
across a 3D display?  Are there pre-defined cross-sections
like the old drafting elevation-plan-section, or is the
cross section on an arbitrary plane?


Stu Wier