circular domain and color scale for Visad 3D display

Hi, All,

Encountered two annoying problems when I tried to visualize the
temperature distribution on a circular plate.

Here the temperature is only discretely sampled across the plate,
first I use the
original (x,y, temperature) data to construct a flatfield, then
construct an Irregular2DSet which covers the whole plate(using polar
coordinate, so can cover the whole plate), then the flatfield
resamples the Irregular2DSet. But the edge looks ugly due to no
temperature measurements at the edge of the plate, and the edge will
be exactly circular if I artificially add some temperature
mensurements at the edge or outside the plate. I guess the reason is
that NaN values are generated for the the plate's region that is not
measured.  Is there any way to fix this(artificially adding extra
sampled points at the edge is not good)?

The 2nd problem: Can we use the SAME color scale for several Visad 3D
displays? (It seems Visad always uses red for the highest altitude and
blue for the lowest altitude for the current display, so any display's
color ranges from red to blue.)

Millions of thanks for your patience and kind help.(Please help, the
project is due soon)

Best,

Qiaolin