Robert
Here is how I do something similar:
private double [] pcMatrix;
ProjectionControl projControl = localDisplay.getProjectionControl();
pcMatrix = projControl.getMatrix();
/**
* Change point of view of a VisAD display,
* using user's input angles (unit = degree).
* Preserves initial scaling and aspect ratios. View from
* "southwest" has azimuth of 225 and decAngle say 45 or so.
*
* @param azimuth azimuth from "north," clockwise, 0 to 360
* @param decAngle tilt angle down from upward vertical. 0-180
*
*/
private void rotateView(double azimuth, double decAngle)
{
// trap input bad values? - not necessary since trig
// functions handle values outside of 0-360 properly.
// rotation around z axis, made from user's "azimuth"
double zAngle = 180.0 - azimuth;
try
{
// rotate in z
double [] aziMatrix =
navDisplay.getDisplay().make_matrix
(0.0, 0.0, zAngle, 1.0, 0.0, 0.0, 0.0);
double [] combo = navDisplay.getDisplay().multiply_matrix
(aziMatrix, pcMatrix);
// rotate in x
double [] decMatrix = navDisplay.getDisplay().make_matrix
(decAngle, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0);
// total rotation matrix is computed and applied
double [] combo2 = navDisplay.getDisplay().multiply_matrix
(decMatrix, combo);
projControl.setMatrix(combo2);
}
catch (Exception exp)
{
System.out.println(" rotate view got "+exp);
}
}
Stuart Wier UCAR Unidata Program
wier@xxxxxxxxxxxxxxxx P.O. Box 3000
http://www.unidata.ucar.edu/staff/wier Boulder, CO 80307
