cam_pos      = [0.344277, 1.81037, 0.837044]';
cam_dir      = [-0.935111, -0.273074, 0.225826]';
cam_up       = [-0.338883, 0.502907, -0.795137]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.137736, 1.09069, 0.748543]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;