code: public double[] project(double[] xyz) {
          double[] coord = new double[3];
  
          coord[0] = cosTheta * xyz[1] - sinTheta * xyz[0];
          coord[1] = cosPhi * xyz[2] - sinPhi * cosTheta * xyz[0] - sinPhi * sinTheta * xyz[1];
          coord[2] = cosPhi * sinTheta * xyz[1] + sinPhi * xyz[2] + cosPhi * cosTheta * xyz[0];
  
          return coord;
      }
docs: Returns the camera coordinates.
  @param xyz the world coordinates.
  @return the camera coordinates.