How to use

setProjectionPolicy

method

in

javax.media.j3d.View

/**
 * Sets the projection mode to perspective projection with the
 * given field of view. In this mode, closer objects appear
 * larger, as in real life. A larger field of view means that
 * there is more perspective distortion. Reasonable values are
 * between 0.5 and 3.0.
 * 
 * @param fov The field of view to use. Try [0.5-3.0].
 */
public static void setPerspectiveProjection (double fov) {
  view.setProjectionPolicy(View.PERSPECTIVE_PROJECTION);
  view.setWindowEyepointPolicy(View.RELATIVE_TO_FIELD_OF_VIEW);
  view.setFieldOfView(fov);
  setScreenScale(1);
  orbit.setZoomEnable(true);
  perspectiveButton.setSelected(true);
  if ((Double)fovSpinner.getValue() != fov)
    fovSpinner.setValue(fov);
  //if (view.getProjectionPolicy() == View.PERSPECTIVE_PROJECTION) return;
}

/**
 * Sets the projection mode to perspective projection with the
 * given field of view. In this mode, closer objects appear
 * larger, as in real life. A larger field of view means that
 * there is more perspective distortion. Reasonable values are
 * between 0.5 and 3.0.
 * 
 * @param fov The field of view to use. Try [0.5-3.0].
 */
public static void setPerspectiveProjection (double fov) {
  view.setProjectionPolicy(View.PERSPECTIVE_PROJECTION);
  view.setWindowEyepointPolicy(View.RELATIVE_TO_FIELD_OF_VIEW);
  view.setFieldOfView(fov);
  setScreenScale(1);
  orbit.setZoomEnable(true);
  perspectiveButton.setSelected(true);
  if ((Double)fovSpinner.getValue() != fov)
    fovSpinner.setValue(fov);
  //if (view.getProjectionPolicy() == View.PERSPECTIVE_PROJECTION) return;
}

/** 
 * Sets the projection mode to orthographic projection.
 * In this mode, parallel lines remain parallel after
 * projection, and there is no perspective. It is as 
 * looking from infinitely far away with a telescope.
 * AutoCAD programs use this projection mode.
 */
public static void setParallelProjection () {
  if (view.getProjectionPolicy() == View.PARALLEL_PROJECTION) return;
  view.setProjectionPolicy(View.PARALLEL_PROJECTION);
  orbit.setZoomEnable(false);
  parallelButton.setSelected(true);
  setScreenScale(0.3 / zoom);
}

/** 
 * Sets the projection mode to orthographic projection.
 * In this mode, parallel lines remain parallel after
 * projection, and there is no perspective. It is as 
 * looking from infinitely far away with a telescope.
 * AutoCAD programs use this projection mode.
 */
public static void setParallelProjection () {
  if (view.getProjectionPolicy() == View.PARALLEL_PROJECTION) return;
  view.setProjectionPolicy(View.PARALLEL_PROJECTION);
  orbit.setZoomEnable(false);
  parallelButton.setSelected(true);
  setScreenScale(0.3 / zoom);
}