cam_pos      = [-0.898643, 1.68459, -0.515293]';
cam_dir      = [-0.194599, 0.00333351, 0.980877]';
cam_up       = [0.00304891, 0.999991, -0.00279359]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [1.30457, -0.00325447, 0.258829]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;