* body around the vertical axis, while your head remains tilted at the same angle.
* @param Angle the angle to rotate around the vertical axis in degrees
*/
public void RotateV(float Angle) {
// Make a matrix to rotate the given number of degrees around Y axis
GL_Matrix M = GL_Matrix.rotateMatrix(0,(float)Math.toRadians(Angle),0);
// rotate the view vector
GL_Vector vd = M.transform(ViewDir);
// the up vector is perpendicular to the old view and the new view
UpVector = (Angle > 0)? GL_Vector.crossProduct(ViewDir,vd) : GL_Vector.crossProduct(vd,ViewDir);
// the right vector is perpendicular to the new view and Up vectors
RightVector = GL_Vector.crossProduct(vd,UpVector);
// set the view direction